How to clear acne when you are 16 years old? How much acne is normal at this age for a guy?

As soon as one pimple gets better another one pops up somewhere else. i got loads of marks on both cheeks and some on my forehead and lots of small eruptions on my chest, shoulders and back and neck. please help!!!!!!!! I tried adapalene gel, but i;m not sure if its working. i've been using it for about 3 months now. I am also vegetarian, and try to keep the acne causing food down, but sometimes i cant resist and eat a lot of fried chips.