I had a mess around with it, here’s what i did:
Marked in blue are the nodes I added to the default player blueprint in the fps scene.
So I am able to trigger the InputQ event by pressing Q on the keypad and that is switching between the boolean being true and false. Then in the movement events I am checking to see if the boolean is true or false before the movement can actually happen. If the boolean is false the player can move, if the boolean is true the player cannot move. (but can still look around because the mouse events have not been modified)