Thanks for looking it over! You're so amazing!!!
I didn't really want to use signals, but I wasn't able to figure out how to connect them until you told me just now. I'm making some other programs as well so this will definitely help me understand the connections better.
Actually, I put the bullet object in there because I was thinking about shooting a bullet towards a ship after each key is typed, but I was having problems trying to figure out how to get the bullet to target each ship properly so I left it for a later time and decided to just have the ship turn red instead.
I was trying to use self-modulate for the sprite instead of the scene root, but it nothing seemed to work for me. I think I'm just too new at this to do it properly. Anyway, I finally did get that part working today, but I'm really not sure how I did that as I kept trying over and over.
The part I was really struggling with was the last part you were talking about. I think I now understand how it's all connected.
I am also going to add in a death explosion at the end as well, so thanks for that!! I'm so excited that it's working better now. I still have a LOOONG way to go, but this is one step closer to understanding Godot.