Hey, I'm 17 years old and I will be turning 18 in July. I used to swim a little, box, and do pushups.

I'm currently taking weight training for my high school gym class but we only get to be in the gym for about 20 min considering changing time.

I am going to college and in sept, I am planning to start lifting weights at the school gym there.

I want to get bigger and more cut. I know that it is the more weight the bigger you get, but if i do heavy weights and i can only do about 5-10 reps, should I decrease the amount of weights?

What kind of protein shake could I buy with a lot of protein and no creatine, because I don't believe in fake muscle? Preferably cookies n cream please.

Thank you guys.

I tried adding pics but they exceed the file capacity.