Try checking Code Like Me, you might find something there i personally go to his channel every now and then to learn something about character movement.
Now i can’t help you much on character movement, but what i know works is that you can make one character with animation and all that and you can make copy of it in which one would have first person cam and the second with third person cam so whenever you switch areas or levels you can set it up in level blueprint or in game mode to possess that particular camera, like in your case when player goes to Hub Area (Third-Person View) have possess set to that player and when Combat Areas (Same camera, but isometric view like in classic RPGs) set possess to that one.