Maybe you could dig into a few open-source clients to see how they work with it?
E.g. someone shared a basic lemmy viewer in godot the other day: https://github.com/sevonj/gdlm - it’s rough but probably not too much to read through. Was posted in /c/godot: https://programming.dev/post/48482
Aseprite for sure! It’s also open source.
there’s a nice godot-aseprite import addon that i now can’t live without: https://github.com/viniciusgerevini/godot-aseprite-wizard - it creates spriteFrames with animations based on your aseprite tags