Gameboy C (and later Gameboy Advance) was actually a big part of discovering programming for me (after QBASIC). I didn't have a great idea of what I was actually doing - lots of copy-pasting, changing stuff around, cargoing, trial-and-error.. But I made stuff happen and it was super exciting.
It's kind of amazing that even 20y+ later, a lot of the resources, tools and even websites are the same as back then. The community is just great.
Reading the OP, I think you won't need much more actually - it's not very complicated, which is part of the attraction compared to modern SE... Just start playing around and see where it takes you. Look at code from other people for inspiration.
I can´t recall what were the main sites for classic GB but gbadev.org was a gold mine and seems to still be around and kicking.
It's kind of amazing that even 20y+ later, a lot of the resources, tools and even websites are the same as back then. The community is just great.
Reading the OP, I think you won't need much more actually - it's not very complicated, which is part of the attraction compared to modern SE... Just start playing around and see where it takes you. Look at code from other people for inspiration.
I can´t recall what were the main sites for classic GB but gbadev.org was a gold mine and seems to still be around and kicking.