Can I use music and sound effects from other people, or do I have to make them myself?
Ideally you would have to make them yourself as the third rule for the jam is:
This is somewhat similar to LudumDare rules for Compo submissions and although it's restrictive there are a bunch of ways to go about it:
HOWEVER! If non of this works you may opt out of the Audio category by mentioning that the audio was not made by you or your teammates on the 72hs of the jam.
This will result in a much lower Overall result since people won't vote on the Audio category.
If possible can you recommend me good music making programs or procedural generation tools that are free and easy to use?