Click enemy and reaction in it's code

Godot Version

Godot 4

Question

How can I make an object react to a click on it? How can I check the distance between it and me in the same code? I would like to learn how to throw arguments in the form of me and the target, but I don’t know where I should find this knowledge

Depends on what you want to do. However collisionshapes have mouse entered/exited signals.

So, you could set up a simple var clickable : bool

On_mouse_entered
Clickable = true

On_mouse_exited
Clickable = false

Input
If Clickable:
Input is pressed
#send signal with arg