I know what you mean, 2 years ago, I waited too long to plan a party.
You could:
-Go to the mall with 2 or three close friends, spend lots of money shopping for makeup, cloths etc etc
-Have a sports party, where you play your fav. sports
-Have a goth sleepover. That would be cool. With your favorite colors, maybe watching movies all night, doing hair and makeup, that would be fun!