Here is the Wikia.

Here's a bullet-point summary that's more accurate to what happens in canon:

• Yuri Plistesky is born and raised in Moscow, Russian Federation.
  
• In his youngest years he starts ice skating. He's walked to and from these sessions by his grandfather.
  
• He moves to Saint Petersburg, Russia, when he decides to take figure skating seriously and work on becoming competitive in the sport. He takes a summer session which is heavy on ballet; he does well, and meets Otabek Altin for the first time. Yuri does not remember this.
  
• He spent the following years training under Yakov Feltsman, earning regard in the Juniors Division for his skills as a figure skater. He is not, however, tight with his footwork. He is also largely kept from attempting quad jumps in his programmes.
  
• He won the Juniors Grand Prix at 14. He also stayed and watched Yuri Katsuki skate, impressed by his step sequences and wanting to see him skate a flawless performance. He originally tries to meet him to get a sense of what kind of person he is; he's disappointed to find Yuri crying in a bathroom stall.
  
• Yuri handles this situation with grace. He kicks the stall door and tells Yuri to get out of the Seniors Division, because there won't be room for two Yuri's next year. (He handles disappointment... like a teenager...)
  
• He was challenged to a break dance off with a very inebriated Yuri Katsuki. Yuri Katsuki won. Yuri himself proceeded to document basically the entire night. ??? Go figure.
  
• He won the Juniors World Championship at 14/15. (He turned fifteen by the time the Worlds rolled around.)
  
• It was decided he'd debut into the Seniors Division the following year, at 15.
  
• Prior to the figure skating season starting, he runs to Japan chasing after Victor Nikiforov, his elder rinkmate. Victor had promised at one point to choreograph a programme for Yuri's senior debut if Yuri won the Juniors World Championship without using quad jumps. (Yuri won, presumably only using triple jumps.)
  
• Yuri demands Victor return to Russia; he accepts the challenge laid out by Victor to compete toe to toe with Yuri Katsuki; to the victor would go Victor. (Supposedly.)
  
• He gains a nickname, courtesy of Yuri Katsuki's sister: Yurio. His Japanese friends continue to use this nickname (alongside Victor) for the next eight plus months.
  
• He loses the competition, leaving before the official results are announced. He returns to Russia to train under Yakov. He has a choreographer brought on board to help design his free skate; Victor's given Yuri the short programme (more or less as promised, despite Victor having forgotten he made this promise). Yuri promises his body and soul to the training for his free skate/skating in general.
  
• Considering his choreographer is a former prima ballerina and ex-wife of Yakov, Lilia takes Yuri in hand and subscribes to the theory that you are made stronger by dying and reinventing yourself endlessly. Yuri trains hard, and starts to look to and listen to those around him for guidance.
  
• Yuri achieved the podium at both of his Grand Prix Final qualifying competitions, silver to fellow skater JJ's gold.
  
• Yuri meets Otabek Altin in Barcelona; later he is saved from some particularly odd fangirls by Otabek, who reveals they've met five years past. Otabek asks if Yuri will be his friend. Yuri says yes, flabbergasted. WHAT IS THIS?
  
• Yuri goes on to break the world record for Short Program points at the Grand Prix Final.
  
• Prior to his free skate, he and Yakov are told Victor plans to return to skating. He's also told that Yuri K. has yet to announce if he's officially retiring or not, and is then hugged by Victor. DESPERATELY. Lmao sorry everyone in that hug looks Distraught. Damn you, Yuri Katsuki.
  
• Yuri then takes gold at the Grand Prix Final by an extremely narrow margin over Yuri Katsuki. His entire free skate is an internal "screw you, if you retire now, guess what? I will make you regret it," aimed at Yuri Katsuki.
  
• He is last seen waiting with Victor while Yuri K. and Makkachin approaching at a run on a bridge in Saint Petersburg, where they are all training. If this is before or after the Russian and Japanese Nationals is anyone's guess.

You know? Technically speaking, Yuri is a loving, curious, and creative young man. Also technically speaking, it is entirely likely you will never notice this because Yuri is also an incredibly defensive, quick tempered, and mouthy young man.

Yuri's initial presentation is reserved, littered with neutral expressions, frowns, or if provoked, outright anger or irritability. He can also be outright rude and/or blunt; usually deflective, and usually as a reaction to his immediate circumstances. (Note, he's not rude to strangers, though he can be thoughtless. He saves deliberately being rude for people he knows on some level or another.) This is particularly obvious around those he feels have slighted or wronged him, such as with Victor or JJ or even Yuri Katsuki; Yuri doesn't have a great deal of tolerance for people screwing around or making light of him or his accomplishments. Or of what he perceives as them to be screwing around. Part of this may deal with the harsh way he handled himself, telling Otabek he disallowed himself from complaining for years because he wasn't yet good enough at figure skating to have earned the right to complain. He holds himself to strict standards, which is hilarious, considering he disdained and/or disliked practice until Yuri Katsuki lit a fire under his butt and he realised the Senior division in male figure skating was a whole new battlefield compared to Juniors. However, this returns Yuri to his initial focus and drive. He buckles down, he endures, and he pushes himself beyond his boundaries to keep achieving better and more. He reinvents himself and his routine to compete with what his competitors are bringing to the table; Yakov and Lilia both ask if he's trying to kill himself when he switches up where most of his jumps are positioned in his routine, and his response is that he has to do this in order to be competitive.

Yuri pushes himself the hardest when he has a goal he's pursuing, when he has a standard that he's striving to achieve, or outdo; something both Yuri Katsuki and Jean-Jacques (JJ) Leroy give him over the course of his Grand Prix series competitions.

The series follows a sort of evolution for Yuri as much as it does for Yuri Katsuki, the titular character. Yuri P. has learned how to reach out and rely on others; he's learned to make friendships, and to foster bonds, that are beneficial to himself and to the other person. Opening up to these people has turned him from being a very lonely and prickly existence into a at-times-less prickly existence who shows his softer, happier side in the spaces he finds comfortable and secure. This is hilariously obvious with Otabek; finding a friend who has already stated he wants to be there to be Yuri's friend, he's animated, smiling, and engaged. Over tea. Immediately after, plopped back into a group setting with fellow competitive skaters (and Victor), he's more quiet, closed off, and less emotive. Up until he has to deride the ridiculous dance contest he'd lost the year before when Yuri Katsuki had drunk-challenged him.

This circles back around to the defensive posturing Yuri engages in. He has a genuine temper, but he also has a genuine love for people such as his grandfather, and a genuine admiration for people such as Victor and Yuri Katsuki. Part of the problem with this is he's also still young, and when he feels like those expectations have been betrayed or let down, he reacts with anger and hurt. In some cases it's more deserved than others. Victor running off to Japan and forgetting his promise to Yuri is a personally painful moment; and it's followed by a realisation that Yuri himself isn't good enough as he is to retain that interest... and probably never was, considering what else he knows. Yuri is a perceptive young man, if he doesn't always make the right call about what he's seeing. He lashes out at safe targets more than the ones he's uncertain about, and figure skating is indeed a safer space; thus he does lash out at fellow competitors, stopping short of engaged in direct physical confrontation. He pushes boundaries, but responds when those boundaries are made firm; a self-assured adult can handle his throwing a fit and he'll settle down into grumbles and ultimately respect. He's not an inherently aggressive person, but he is also not one to fail to challenge what he sees and demand what he considers to be his dues out of the world.

Yuri is also the major bread earner for his family; meanwhile, only his grandfather is ever mentioned as attending any of his competitions. Considering the expenses of his lifestyle, that he's also supporting a family he doesn't see is kind of startling. It's a major responsibility for a teenager, and he doesn't even talk about it. He simply focuses on what he must do: win. Be confident in his skills, and win. Push himself harder each time that confidence is shaken, and win. Face his own frustrations when he realises that his best might not be good enough, then find a way to best himself so that maybe, maybe it will be.

Because, from start to finish, Yuri is a fighter. Otabek is the one who says that at ten, he'd seen Yuri as having the eyes of a soldier. It strikes a chord with Yuri, quite visibly so, and it's a succinct summation of how he approaches the world. Fighting to keep and carve out a place of victory for himself. Fighting himself, to stay competitive. Fighting against the clock, as his body's natural changes through puberty will necessarily reshape how he skates, and perhaps even leave him as a less competitively viable skater than he is now at 15/16. There's a great deal of fear and reality he faces down because he must; and he does not give up. Through blood, sweat, tears, and everything else, Yuri makes himself go on, and he learns from the people willing to teach him.

Just as he is willing to teach in turn. For all he couches things in grumpiness or in mild-to-major insults, he still doesn't turn away from Yuri Katsuki when Yuri is asked for his help in demonstrating how to land a quad salchow. Instead he shows Yuri multiple times, trying to both explain and assist his competition. Because he loves his sport, and he does want to genuinely reach out to the people he respects and admires. Yuri Katsuki, perhaps in spite of the sour taste left in Yuri's mouth the several months prior (it must be what, April/May, and the last he saw Yuri K was in December), is someone whose skating Yuri respects. That admiration for Yuri K's step sequences didn't disappear; his desire to see what Yuri K pulls off when he skates flawlessly remains consistent throughout the series.

Yuri still defaults to a more neutral to crabby demeanor, keeping people at a distance unless he wants them to be close. He doesn't seem comfortable with his fans, to any degree; he endures them under Lilia's lecturing, but he'd much rather not get dragged into whatever they've got going on. He's not in this for the fame; he's likely into skating for the love of figure skating, and for the pressing need of his family, somewhere in the background.

He is also a teenager, and it shows in his impulsive decisions or poor decision making, from deciding his best way to hunt down a missing person is to walk through town shouting their name, to deciding that the best way to greet someone is to kick them and then offer them food or his version of angry, biting vitriol; only to follow with the more honest reasons why he seeks out their company, offering gifts, or concessions, as to what it is he understands of their goals. See him with Yuri K after the Russian Cup, giving the older skater pork cutlet pirozkhi made by his grandfather, aware enough of Yuri K to know it's also close to his birthday. And wanting to share, with someone who also enjoys pork cutlet bowls, this achievement of his grandfather's. While also wanting to complain about how frustrating it was that he did the best performance yet of his skating and still came in second after JJ. His age also shows in his anger and tendency to get ruffled feathers over insults both real or imagined.

Yuri is trained in ballet; Lilia Baranovskaya takes over his training for his debut in the Seniors bracket. He is probably familiar with other forms of dance. He at least believes he can break dance, considering he's drawn into competing against Yuri Katsuki after his last Junior Grand Prix Final. He is a professional grade competitive figure skater; his flexibility allows him to pull off spins and spirals difficult for many fellow male skaters. He's also known for his jumps, but until his recent training, his step sequences were passable rather than inspiring. Now they're also entrancing? Enthralling? Beautiful? Strong? Largely spite fueled? Turns out that his free skate is best when skated with some kind of anger burning under the surface... as opposed to his short program.