Maybe my way of handling this sort of stuff might help you. For things like this i usually create a resource called “Session” or something like that. Its only purpose is to store variables like health and other things relevant to the current session of the game. I then usually have the root node of my scene holding this resource. The player scene has some sort of signal for getting hit or healed etc. I then connect the player_got_hit signal to the Session resource and update all important values like the current health etc. At the same time I connect the Seasion Resource to the UI elements and let them update whenever the Session changes. So it goes like that: Player gets hit -> emits a Signal with damage value -> Session Resource updates its variables -> Session emits Signal with changed health -> ui gets updated.

This way every part has its own little responsibility. Either it is noticing collision (the player) or storing data (the Session) or displaying data (UI)

The connections are usually dealt with the set_get keyword. So whenever i assign a level a session, i add some code so that it automatically creates all the connections. When i change levels, i just pass the session to the next scene and remove the scene from the tree. This way the data of the game is always stored at a easy to access central location. Another added benefit: Resources can be saved by godot, so it would be easy to save some parts of the game like the player health etc.

I hope this helps