NRA COMPETITIONS HELP NEEDED!?

I'm 15, I want to get into rifle shooting competitions. I don't want to look on the goddamn Internet all day looking for the right "event". I want to shoot ar15 type weapons at targets down range. I don't care if they are silhouettes or not. What kind of rifle should I buy though? I don't want a .308. I don't mind having bolt action or an m1 type weapon. What event should I enter into with these weapons?