Feel free to practice, or keep working on your own projects, but please do not make games/assets specifically to use during this jam, because that's not really in the spirit of a game jam. (And it's against the rules.)
You'll already have access to all of your previous work, as well as the game templates and starters in the engine, that you can snip pieces from to use in your game. So creating new games/assets specifically for the jam, which is against the rules, shouldn't really be necessary.
What I suggest you do though, is look around for asset packs, music, sound effects, and tools you might want to use during the jam. (That can also help you later in other things you want to work on, because you'll already have a library of assets/tools that you know you like. 👍)