One of the things that can hold you back in making your own indie games is the art. If you want to get some decent starter packs of 8-bit art that’s free then here’s a decent resource I found:
They also sell other packs, but these will be good enough to get started. The only problem I’ve had is how exactly you pull these into PICO-8 or other consoles. I’ll have to research that and get back to you.
I forgot to also include the PICO-8 forum sections that have code, graphics, and sound effects snippets:
Code snippets:
https://www.lexaloffle.com/bbs/?cat=7#sub=9
Graphics:
https://www.lexaloffle.com/bbs/?cat=7#sub=14
Sound:
https://www.lexaloffle.com/bbs/?cat=7#sub=15
I would say if you use these make extra sure they are royalty free or open source in some way. Otherwise, you can probably use these to learn by copying and trying to understand the code.