This is a questions I haven't seen anyone talk about. I practice speedrunning minecraft and, never actually beaten the game before. So that's why I ask this question, but I would call myslef decent at the game. I have seen a youtuber who hasn't played minecraft in 6 years, who started speedrunning and with practice he actually managed to do some good runs. But I still think this question needs to be answered.

Nobody's good at a game when they start speedrunning it. Being good comes later.

There are no rules for skill level when speedrunning. You just need to make sure everything you do follows site rules and leaderboard rules