You could consider
1. Decide your budget first, you can either stick to that or ask your parents or friends to contribute.
2. Sleepover, around a theme, ghost stories, charades, chiclit or horror movies, with finger buffet foods, such as pizza, chocs, jellies etc (ask each person to bring a dish as a contribution)
3. Fireworks and bbq in the garden
4. Visit to a local place of interest/museum (some are free of charge)
5. Block book for a matinee at the theatre
6. Book a group free makeover at the local department store, get free advice, samples and discount vouchers for future purchases, then have afternoon tea and/or coffee
Happ Sweet 16 when the day arrives, Posting a birthday smile for you.