Wonderful progress! I see so much potential in this project. I understand everything is very early on, so any feedback I have is minor. I think you're on track to build something really cool.
I'd appreciate being able to ride the horse in the larger field area. I kept having a problem where the horse would get stuck in the doorway. Maybe a button that summons the horse as long as the player is outside?
Other than that, fullscreen would be appreciated. At least on Windows, Godot games can have some pretty inconsistent performance when windowed.
I'd personally love to contribute to the game if you're looking for any sort of environmental art or 2D/3D assets. I am not skilled at animation, but you can check out my profile and see some of the work I've made.
if not, that's cool too! Keep up the great work.