You don't need to cut to 7%. Don't listen to that.

But your age, yes. you run the risk of damaging your endocrine system. and unless, ED and fatigue sound like fun, i would stay away from AAS right now. Here's a good read and there's many more. You can do a lot right now w/your natural hormones, a good diet and solid training. Nevermind the read, i see odins already put it there.

Good luck. Stick around and do some more research. There's a lot to learn and a lot to lose if you don't do it right.