the player and the dorr are in diferent scenes
I assume you mean they are both separate scenes. If the are in different scenes the player obviously cannot touch the door, same as I cannot touch you because we're sitting in different rooms and probably completely different parts of the world.
If your player is a KinematicBody2D (or a RigidBody2D) you only need to connect the
body_entered-signal of an Area2D representing your door to a callback:
If your player is an Area2D as well, you'd connect