I sympathize - even having endured high school a long time ago I know what you mean. High school can be a difficult time - unlike the way some movies portray that period in a young person's life.
FSU was completely different for me. There are no high school like cliques (except maybe the social frats and sororities to a certain degree) and as a freshman you have a clean (social) slate and a chance to make lots of friends.
You'll probably find it to be like taking all the motivated students from your school and concentrating them in one school. Suddenly, everyone is motivated and focused on academics. You'll find you tend to have lots in common with most all students.
It was fun.

(and a lot of work

)
This transition is why staying in one of the on-campus dorms as a freshman is so interesting. Meet folks, have interesting conversations, make friends and have some fun.
Oh - and don't forget to study...it ain't high school any more.