I've got an M5Paper laying around and something I've always wanted to build for it (for myself), but I never quite figured out a good dev setup or starting poin

I've got an M5Paper laying around and something I've always wanted to build for it (for myself), but I never quite figured out a good dev setup or starting point for development. If this had some sort of personal use version it would be perfect, but I understand well enough that there's no money in that.