Highschool Cliques?

Now, people keep telling me:
"Don't be in a clique! They just talk trash about others! Be your own person."
Yes, yes, I agree. I want to BE my own person.
I just want friends.
All my friends went to a different highschool then me.
Don't get me wrong, I have friends from the highshool I attend now.
Just not a "Clique" how everyone says it. (Or a "group")
See, i'm NOT shy person. You have to get to know me.
I'm actually really funny and outgoing.
But I don't know anyone in 5 or 4 of my classes.
Everyone has their groups already though, so I don't fit in.
My friends at my other school tell me they have their groups already.
You know, their hanging out with new people, sleepovers, etc.
BY THE WAY! I'm a freshmen. :) Haha.
So yeah, what can i do to fit in more. Besides the obvious, "Be myself."