It can be as simple as a happy birthday party. Yes, you're turning 16 but you don't need to go into all that sweet 16 stuff. Just have a nice gathering with family and friends and be happy about turning such a fun age, Don't over think it.
Being a kid does suck at times. It's probably the hardest part of your life. But you can make the best of it by keeping a positive attitude. I know this doesn't answer your question but I'd like your 16th year to be the best. Good luck