Does the venue cater food and drink? If not you could perhaps provide Mocktails which are growing popular with teens at the moment and are basically just alcohol free fruit juice. You can probably find a ton of recipes for them and that would make them feel grown up, especially if you served them in plastic "wine glasses".
Sweet buffets are a good way to go, again you could self cater by just buying a variety of multi packs of sweets from Asda or your local supermarket and not having to spend much, alternatively you could provide pizza (even cold pizza is nice) and other party foods.
Obviously keep the venue moderately dark, I'm assuming there's a dj and a set out dance floor?
Music is important, get your daughter to find out what everyone's listening to at the movement (consult MTV) and create a playlist of songs you want to be played which will add to the enjoyment for your guests.
Obviously still keep the traditional dance songs such as Macarena as you'd be surprised how many kids love getting up and dancing to it.
Mostly the guests are just kids and so they'll probably take "selfies" most of the time.
Invite a lot of people, both genders if possible. Encourage her to try and invite people she might not be best friends or have known her whole life, it might help her make new friends.
Help her to gain confidence about it and to be excited. Her guests will follow her lead if she's excited for it.
A few more ideas:
- Provided party poppers, you're never too old.
- Make the timings clear on the invites, don't personalise invitations and let your daughter just hand them out to whoever she wants.
- Like I said, make sure the music is modern, a good dj is key to a good party.
- Try and at least provide one form of food or drink, guests will get hungry and thirsty.
- There's going to be a lot of kids there, and kids want to feel like they're free and without too many adults. So if you can try and keep the adults in a specific bit and allow freedom to the kids.
- Decoration, if it's a dull room add some decor!
- Obvouisly the kids are a little old for party bags but you could offer little bags of sweets as a "favour" and thank you for coming.
- Whatever happens, remember that it's your daughters day and she should have fun. No matter how the guests feel it's about making sure your daughter has a good time.
Hope I helped, best of luck.