Hello! In fact that is rather basic - you can create BP with ASkeletalMeshActor, create two funcs in it, for example OpenDoor and CloseDoor. Both can be implemented just with PlayAnimation node of USkeletalMeshComponent. But this is only from animation point of view. It is not optimal, if you will calc collisions by skeletal mesh
You can open Level blueprint and add E event. After that open Level viewport and select door actor, open Level blueprint, Right Mouse Button(RMB) - select Create reference to Door actor (the first option in list), after that just call Open/Close funcs, that were mentioned above