It depends. You don't have to come out to anyone you don't feel comfortable coming out to. If it is to parents, come out if they are accepting and you are comfortable. If they are not accepting, it would probably be best to wait until you are older and more independent from them.
I came out to around 10 people at school last year (I was 13) and a lot more from the past two school years indirectly, if it came up, not hiding my relationship, those kinda situations. You're not too young to come out, if you feel ready, go do it, but if you aren't, then don't. Also, make sure you're aware of your area and school's stance on the LGBT community because if they're homophobic, some people may make fun of you and it can be really unpleasant.
I think it all depends on your safety. If you feel your parents would be ok with it and your school is a safe place, I don't see why not. As a teacher, my advice is to be confident with your decision. I usually see that students try to pick on the students that are very insecure. If I see this behavior I will stop it. I have a student who is gay. From what I've seen, students dont pick on him because he has owned it. "you're gay" doesn't bother him because it's true; he is gay. Students don't use that against him. If you are confident with your decision to come out, you will be fine. I will also add that there is no rush to come out. I did not come out until I was 20. Do it when YOU are ready.