Make sure you keep your hair (especially your bangs since you said your forehead is where the problem is) clean. If your hair is oily, the oil will be passed on to your face and if your face is oily, that'll cause acne/breakouts. It's normal for people of all ages to get acne (yes, even adult acne exists). There's a lot of stuff you can do to get rid of them. If all else fails, you can go to a dermatologist (a professional skin doctor). They'd be able to help you out. Something natural you can try is green tea. If you don't like tea, you don't have to drink it. Just get some pure green tea bags and do everything you would as if you were making a glass of tea. After the tea is ready, dump it (or let someone else have it) and squeeze the tea bag out. Let it cool down just a little to make sure it's not too hot, then rub it in circular motions around the acne affected areas. Do this once a day after you've cleansed your face. Here are some basic skin care tips you can use to help you have clean/clear skin -
Wash your face twice a day - once when you get up, then again before bed. If your acne is severe, use a special acne wash. If it's not all that bad, just use a basic, non-acne cleanser. Wet your face with warm water (warm water will open your pores and allow the cleanser to really go deep and clean your skin thoroughly). Then apply your cleanser to your face and neck using gentle, circular motions. Rinse your face with cool water and pat your skin dry (you should pat instead of rub because rubbing can cause irritation).
Use a moisturizer. During the day, one with SPF is important. SPF helps protect your skin from the harmful affects of the sun. You should wear sun screen on your entire body daily, even in the winter (the sun is still out even when it's cold). Use a non-greasy formula. If you're using an oily lotion that doesn't absorb well, it can cause acne. At night, get a cream-formula moisturizer. A cream formula is thicker than a basic lotion-like moisturizer. It's important to use a cream at night to allow your skin to keep it's natural moisture levels.
Exfoliate your skin regularly. If you get a scrub that say it's ok for daily use (like Aveeno), you can do it everyday. If you have sensitive skin, you might want to only use it every other day or only a couple times a week. Exfoliation is good for you and helps remove dead skin, keeping your skin looking nice, fresh and smooth. It can cause irritation if you do it too often or if your skin is sensitive. Never do it more than once a day.
Make sure you change pillow cases often. If you use the same pillow case over and over instead of using a fresh one, you'll keep getting dirt on your skin even after you've cleansed it.
Make sure you keep your hair clean. Like I said already, the oils from your hair can get on your face and cause acne/breakouts.
If you're going to pop/squeeze pimples, do it correctly. First, wait until it's ready. When you can see/feel stuff in it, try to gently pop it. Make sure your fingers are clean before you do this. If it pops, squeeze all the junk out, then wipe it off and leave it alone. Some pimples need popped more than once. It depends on how big they are and how much stuff is in them. If you pop it and you see blood, it's ok. Just stop messing with it until it closes and more stuff is in it.
Avoid touching/rubbing your face. Oil, dirt and germs from your hands can get on your face and cause acne/breakouts. If you have to touch your face (like before you cleanse it) be sure you wash your hands thoroughly with warm, soapy water (preferably an anti-bacterial hand soap).
I hope all of this information helps you. If you need anything else, message me!