I am a total newb in the (app) development space, just starting out.
I would like to participate / contribute. What would you recommend to do?
I recommend participating in the Nut November hackathon, especially if you are a newb in the bitcoin app development space: https://nutnovember.org/
Discussion
One of the best projects I made in the nwc space was my nwc tester: https://github.com/supertestnet/nwc_tester
It lets nwc devs test their apps for compatibility with various nwc specs.
I think it would be very cool to have a similar app for testing compatibility with various cashu nut specs: https://cashubtc.github.io/nuts/