I figured I would show an example of another way this could be designed for anyone else thats interested in a different way to handle shooting from the player character 
Create a Node2D under your player and call it ShootPoint.
Position the ShootPoint wherever you would like to shoot projectiles from.
When choosing to shoot a projectile u can just choose to instantiate the rocket or any other projectile you add to your game at the players ShootPoint’s current position.
Creating the Shootpoint variable and setting it with @oneready (This can also be manually set with the @export, but i always try and handle everything through code if possible) as well as defining what type of variable this is.
Instantiating the rocket at ShootPoint position
Hope this helps and good luck making a game!