How do I improve my game

I'm 18, 182 and obviously heavy. I'm a toproller but I want to improve more. Could pronate for 10 and static hold 38kg but I still lose to some small classmates. What should I do to improve more?

I'm 18, 182 and obviously heavy. I'm a toproller but I want to improve more. Could pronate for 10 and static hold 38kg but I still lose to some small classmates. What should I do to improve more?