Well my ideas may be useless but something simple can sometimes be the funnest partys
Like a few years back my family rented out the local health club for the evening and had dance classes going on, swimming, workout sessions etc. and it wasnt that much fun...
I bassically invited all the kids in my grade and lots showed up but I didnt get to really enjoy anybody...
Then this year we procrastinated too much so we didnt get it booked in a timely matter so we ended up just doing a small party with 5 of my closest friends and it was so much more fun
We went to the local pool and then went to my house and everyone spent the night
We could enjoy ourselves and all
I think this year I'm going to invite maybe my life group over from church and maybe a few other friends and I think that should be quite fun

Maybe just play video games, and just enjoy each other
Then have them spend the night...
Something simple is sometimes so much more fun just my opinon...