Can someone help me plan my Sweet 16?!?!?
An indoor water park is a great idea. They usually have great packages for groups.
The things you list aren't what I would call "affordable". You'd need to ask your parents what you can do- but think smaller. You could have a better time with just your *real* friends, never mind the rest of the people you're thinking of inviting. You could go do something adventurous- a rope challenge course, or rafting, or kayaking or something sophisticated- go all dressed up to a fancy restaurant, or to a concert, or to a museum. You might also consider doing something for others. Form a team and do a benefit bicycle ride or walk. There are kids who have done that, and they were awesome. Gather donations in honor of your birthday, and donate your time and energy knowing it will help someone who needs it. There are so many ways to have fun. It's up to you.