Well, you’ve certainly come to the right place! Here is a good intro to thumb assembly, which is most of what you’ll be using (THUMB is a subset of ARM assembly, which is also used in the game, but by the time you need to mess with anything involving ARM you’ll probably be able to figure things out by yourself). Here is a thread detailing the battle routine. The discord is a good place to get help, as well. Pretty much everything you’ll need (and more) can be found in the Unified Hacking Dropbox.
Looking forward to seeing what you come up with!