What are the key ingredients to look for in any acne product that will not clog pores in oily skin?

I drink lots of water.

How about vitamins? I don't take any (I'm a teen) and don't know any about them. Which ones should I take??

Mixing prescribed acne medication and normal stuff–is this good/bad?? Does it affect your acne?

ANY TIP HELPS. THANK YOU!