Help with planning a Halloween party?

[MakeRoomForMyAwesome]

Sorry, it's a very long question, but please read

So me and my friends decided about a month ago that we really wanted a party, as it had been a while since we last had one. Then we thought Halloween is just around the corner, so why not have a party then? What I need help with is things like what we would need and everything.
Venue is done, invites will be on Facebook/ text, I might be able to get party lights and a smoke machine and my friend is getting speakers, so we'll just use a playlist on Spotify or something. What we need is food ideas, drink ideas, decoration ideas (not childish like cute spiders and witches please), and anything else that you think should be on the check list.
Me and my friends are nearly 15 so it won't be anything like shots of tequila and stuff.
Do you know of any good Halloween songs? Like Monster Mash or Thriller?
Also, we don't want to spend a fortune, so if you could suggest make it at home things or stuff we can get from the £1 shop then please do
AND! I need costume ideas? Single ones, paired ones and groups ones please, so any at all!
Oh and do you know any good games for a bunch of teenagers at a party? We might not do games, it's just a thought. Should we do games? Or just get on with the party?
Thanks, if you made it to the end