Ahhhhhhhhhhhhhh Help, Guy problem??

I am 15 years old. I have never dated, I believe i am still alittle young to date, and it will just interfear with school and My fav sports (baton twirling, horseback riding). I have been asked out 3 differt times already, But i Simply told them no and that i am sorry. But now theres this anoying kid that no one likes that much, he likes me. And its all because i did not make funn of him when i was in elementary. He smells, and is alittle crazy, He hit a kid with a chair cause he was being anoyying. Now everyone makes fun of him. I always felt bad for him. But I happen to be positive he likes me. He has been following me( he does not know I know) And been coming up to me and talking to me. The reason i know he likes me, cause i was standing right behind him when he said he liked me to someone. He does not know i know. Now everyone is saying if he asks me out, i have to say yes cause he will prob do something crazy. I am not gonna say what my friends are saying, but guess. He is Crazy!