Your'e going to be a teen. You need to have the coolest party, and by all means...it's necessary :)
The greatest 13th b-day is a pool party..depending on what month your birhtday is in. Otherwise...have a dance party.
Dance Party: Bring all kinds of music and have light snacks and dancing contests and prizes. You can ,even invite boys and have a sleepover after the boys leave.
Snacks: Hot wings, celery, chips, candy...things like that.
Pool Party: Always have pool games that people who can't swim very well can join in on. Also have pizza and if possible music on the side.Remember to provide pizza that is suitable for everyone and have a subsitute selection, such as a sandwich. Another poolside favorite are create your own subs. Have a grownup who can swim around if there are any problems.