13`th Birthday Ideas!!

Heeey,
So my 13`th Birthday is going up in the end of November but I have to start planning now !!!
I want to have a party that every one is all fansy and all the guys have to dress up... One of my friends already did a mask ball thing so I cant use that theme.
I have to make my party really big!!!
But not go to expensive.
If you have any ideas please let me know !!
- Thankss
Kirsten:)