Hi,
Unity + Pixel Art is a solid combo for a jam! Don't worry about being a beginner, jams are the best way to learn and build your first portfolio.
I built GameJam Crew specifically for people starting out. It helps you find teams that match your engine and level without the stress of messy forums.
You should definitely drop your info there and find a squad to grow with: https://gamejamcrew.com/
Good luck with the dev journey!"