Use a node called CharacterBody2D.
This node has functionality built in, such as
physics and the ability to detect collisions.
Add a Sprite node as a child
Use the Player.png as the texture
Rename the CharacterBody2D to Player
Rename the Sprite2D to Sprite
Add a CollisionShape2D as child of Player
Add a rectangle shape to it.
Cover the Player with the HitBox