As a pro-active approach when our daughter was somewhere around 11, we went to the dermatologist to get a heads up and be ready.
Dr. Menter and his group at Baylor are awesome. Great Dr.s.
My daughter is 15 now and has flawless skin....(not by chance...she works on it. We have gone to Dr. Menter every year since she was 11 or so for a check. She uses Duac on a daily basis. The Rx comes with a face wash as well. It is pricey....I have a mail in Rx and pay $100 for 3 months worth...OR if I mess up and need it asap, it is $40 a month.
Proactive did not work for us, it was too strong.
Clenasers that the Dr. recommends are also very reasonably priced at Target, grocery stores, etc Purpose, Cetaphil are 2 of the best. Nutrogena is also a good one.
We are avid users of Clinique products (also Dr. recommended). You are guaranteed if you don't like them you can return them. They have an acne wash that daughter uses and a moisturizer which is a gel which is good for teen skin.
We are very diligent on face washing at night and morning. It is habit your son needs to develop. It helps a lot to maintain the skin.
Good luck!!