I'm 14 and need some exercise routines..?

I'm 14, going into high school, and I plan on going into my 3rd year in athletics. High school coaches are really tough, so I've heard...And I need to prepare for that. I weigh about 160lbs and I think that's too much. I want to do power lifting so bad. Any help and/or ideas on how much weight I need to lose and how I can do so? Thanks!