Make-up is the last thing you want to be putting on your face if you're worried about getting pimples. You're a teenager, you're going to get a few spots every now and then. They're really nothing to be embarrassed about. Great that you don't normally wear makeup. :)
One: I'm glad you don't normally wear makeup. You are already naturally beautiful like every other woman I ever met. Two: Acne happens. Now you dislike it when it happens to you, I hope you don't make fun of others when it happens to them. (Unless it's your close friends. That's what friends are for)
It's true, becuase all the oil and stuff in the make up gets inside the pimple and makes it worse, becuase the reason pimples form in the first place is becuase of oi on your face, and adding more oil via make up makes it worse.