To create a new slide click on either of the two marked buttons, this will populate the new slide crearion menu.
Fill in the name of the slide you wish to create. Then click on create
To edit the name of an existing slide click in the marked slot.
To position the VR teleportion spot, select the slide and a gizmo will appear in the center of the 3D viewport. Position the gizmo in the desired location in the 3D space. When published to VR the gizmo position will be an active VR teleportation spot.
To delete a slide select the slide. Then click the delete button on the ribbon
You can assign Actions to a slide, to do this first open the drop down Actions menu by clicking on it.