>>717673462
you learn how the mechanics work (pay attention to the in-game tutorial if it has one) and find a character you connect with and learn them by playing matches with others combined with training mode or the new fangled replay takeover when you hit a wall or confused about something from a real match.
since you mentioned Tekken, think about how that game handles basic movement, defense and offense. And to learn a character, find out what their best 10 - 15 moves are and use them through rote memorization and try to land them in a match. try throwing them out in a range that only the tip makes contact with the opponent so you know when and when not to throw it out. you can add more moves little by little to your toolkit. then look up which moves are good punishes (stronk moves that come out in 10-15+ frames that will guarantee a hit after blocking an unsafe attack).
After you learn a character front and back and feel comfortable using them in real match, you can start paying attention to what the opponent's character is doing.