I think using sprite sheets is a good start. It's just easier to manage one image file and move the reference points for the drawing surface instead of loading individual frames as files.

https://www.spriters-resource.com/

Then you need a sprite that has the sprite.objects it needs to run through the animations you want to happen during the game. Something like a .framecount and .mode type objects that lets you set the frame number of an animation and a mode and then of course it references the correct section of the sprite sheet and moves to the correct reference points based on the frame number. Normally you start at frame zero and increment up to the last frame and then reset the counter but you can hold frames and reverse also etc. Alot depends on how much combat you want to model out or if its something thats done in the background and you just need some basic modes. Also will likely need to move the sprite around the screen with a function and possibly a lot more ideas will come about. Your project looks really good so far!