The problem is “get player character”.
There’s the distinct possibility that whatever you fish out has no movement component.
add an is valid? Test before using the value. And add an error print out with a print string if it isnt valid.
If it isnt valid, your character (whatever the engine thinks it might be) doesn’t include a movement component.
Yoy should aslo have an isvalid? Check on whatever the character is. There’s no guarantee the function will actually fish out a character you are controlling.
You probably also need a bit more experience before you delve into setting up movement.
As far as the tutorial goes, it seems fine. Should still work as expected if you use the default stuff the engine comes with and don’t add steps to it (like making a custom pawn instead of a character).
but as you just figured out, it doesn’t follow any of the best practices it probably should (being official documentation).