Welcome and 21 is a perfect time to compete. I did my first show at 16. Competing in strength sports or bodybuilding doesn’t necessarily mean taking drugs. Especially in 2021! Now, if your 10% at 165 then if your natural(i hope you are) then get on the dais at lightweight. It differs for most people but a shredded 150-152 can be achieved pretty easily. Then you can go diesel after and seee what you look like as your gaining muscle.