Hi Kas!
To be honest, the way of multiplayer in VR is exactly the same as in Desktop. SO common tutorials on multiplayer should also work for you. Simplified speaking, all four sessions related blueprint nodes should be used. You should also be familiar with UE game framework (like gamemode, player controller), since they manage the multiplayer login etc. For switching to a new level, use execute command node with ServerTravel LEVEL_NAME?listen
But debugging multiplayer with two VRs is a nightmare. You need someone to help you or you can use some keyboard input to trigger some events that should be triggered in VR.
Hope these experience could be helpful to you.