How do I make friends?

I'm going to be a junior at my high school this year, and the truth is, I have no friends. I don't see whats wrong here! I'm on Varsity Cheer, I'm fun, nice and personable but I have no friends. Although I do have one best friend, and a boyfriend, their really all I've got. I want this year to be fun and exciting! I want to make more friends but I don't know how to go about it. So please help me! It will be very well appreciated!