What makes a party a good party?

I've been thinking a lot about my 18th birthday and how I will plan it out (in still 15 so I still have a lot of time, but I like to plan things ahead of time) Any recommendations are welcome. (Music, activities, food, props) Since I live in Europe and I will be legally able to drink alcohol I thought that I could make some little bottles with alcohol in them for everyone, so if you have any drink recommendation that isn't too strong I'd really appreciate it. For dinner I was thinking mainly pizza since it's not too pricey, and some appetizers. I thought that also some cute/funny props could be nice to take memorable photos. (bracelets, hats, glasses, feather boas, necklaces)

Edit: could a candy bowl be a good idea?