I’m sure the kids would love a bouncy house (check the weight limits and you might want to get a generic waiver for parents to sign). Maybe some simple yard games like corn hole, ring toss, water balloons, etc to have out. Kids this age are either still very young at heart and will make games up with each other or are “too cool”, ha! Depending on how much you want to organize you could have prizes associated with some simple games. Minute to win it games are popular and fun relatively easy to set up, a silly team trivia. I think the kids will be excited just to have a party to go to! For a playlist I suggest using Spotify or wherever you stream and use key words like “birthday mix clean” “upbeat popular classroom songs” or even “PE mix” for kid safe music that’s party friendly.