Try not to assign ‘wrong causes’ to things. It’s not that you don’t have a boyfriend because you’re ‘silly, crazy and overweight’ (assuming you really are all of those things). Lots of girls and women who are all of that and more have great relationships. You probably will, too. It’s a function of time, and meeting people, and being someone that people want to meet.
One of the best pieces of advice I ever got about starting a relationship (and it’s hard for even many adults to follow, so it may take time for you to get it and incorporate the advice yourself, if you even want to), is “be interested, not interesting”. In other words, don’t try to be ‘a character’ that people are interested in, but be interested yourself in other people. For one thing, it puts you in charge of more relationships rather than waiting for someone else to take an interest.
And yes, in my opinion, you are too young to be worrying much about ‘boyfriends’ anyway. Don’t rush things. You have a long life ahead of you, and right now, believe it or not, your education is far more important to anything you want to do later, and even to any good relationship you want to have later.
Good luck.