You've probably heard this before, and it really is good advice. The most important thing you can do is consult with a trustworthy dermatologist - these people are trained professionals and can tell you what's right for your body. What if you have an allergy that you had no idea about? Exactly, that's why it's so important.
Now that that's out of the way, let's explore a few things you can do on your own, even without a dermatologist. First and possibly most importantly, start washing your face - but despite popular belief, in this case more is not always better. Wash your face in the morning, perhaps once in the day if you get a chance, and before you go to sleep. That's really all you need to do - otherwise you might be making your face even more susceptible to an outbreak. That does sound strange, but by over-washing your face, you'll be drying out your pores and removing some of those good oils that your skin produces. Instead of washing your face twelve times a day, try doing that with your hands. Keep in mind that your hands are constantly in use - door handles, pens, food, your dog or cat. The average person touches their face constantly without even thinking about it - why get all that gunk in your pores?
There's quite a bit of controversy regarding the correlation between diet and acne problems. Some researches will say that there isn't much of a link, others will say that it means everything. In this author's opinion, that's because of our primary idea here: everyone's body is different! So your friends might be able to eat as much junk food as they want and never get an outbreak, but you have one cheeseburger and the next morning you have a couple of pimples. If you're not sure, your best bet is to eat healthy for a week (come on, it's not that bad!). Plenty of fruits and vegetables, and absolutely no fast food. If it makes a difference, you know what the catalyst to your acne problem might be.
Most people have acne trouble (even adults) so don't feel badly - just take the necessary steps to figure out what kind of acne treatments are best for you, whether they're do-it-yourself steps you can take at home, or taking the advice of a medical professional.