You dont need a boyfriend at school. School is for getting your head down and doing the best you can for yourself.
Alot of guys in your school will be immature. Im 16 and have left.
Yes, I don't recommend getting into a relationship with a guy under the age of 17. That isn't a rule, but on average, those guys aren't very mature. I'm a guy, if you were wondering. I consider myself more mature than the average also. However, if the goal is sex, and not a long-term relationship, then by all means get a boyfriend. How you appear will affect what type of people you attract, sounds obvious, but some people don't understand that.
Relationships are as different as individuals are. To "get a boyfriend" just to have one is the wrong reason to get one and will result in heartache. Choosing a boyfriend should come naturally. When you find a boy with whom you like to spend time with and he feels the same way..it will work itself out. Just be patient, your time will come.
Make sure you do it for the right reason. If you want physical experience, emotional closeness, and companionship, then I'd say you should just relax and let your mind select someone you like. Then, show interest. If, on the other hand, you feel pressured by social needs or status, just drop it. It's not worth it.