Use the BP Node “Try Get Pawn Owner” and cast it to Character.
Having said this, let’s continue with a general rant:
GetPlayerCharacter(0) is used way too often and sometimes totally inappropriate. It is true that unless you have a splitscreen game, Index Position Zero gives you the local player’s character. If you use this in an animation sequence, this always gives you the player’s character, even when the current actor is not the player itself. Consider what happens when you place a KI Character with the same animation sequence? Or in a multiplayergame, when the other character initates a Jump (yes, then the data from your local player is accessed, which of course is wrong).
It’s bad design and prone to errors, when you just go for GetPlayerCharacter(0) for stuff that is clearly owned by something (which does not necessarily need to be the player!). Features like HUD and Animations give you methods to identify the owner of such object, so please use them!
PS: Look at how it is done in the Animation Graph “FirstPerson_AnimBP” in the FPS Example.