Set up the Player. 

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