Yes you can walk around in free mode or teleportation. Some of the project templates unfortunately have blueprint variables that maybe deactivated. You need to enable them. Also enable the appropriate plug-in for your VR headset. If you looking for tutorials there is a nice VR walk through on the Unreal Online Learning website. It makes use of the teleportation mechanism for movement using Navigational meshes to constrain player position. It also covers interaction with objects.