If your goal is simpler, to build a virtual reality world and share it with others as a shared social experience, you can use one of a number of existing social VR platforms that provide the infrastructure and allow customization. Among the best, VRChat is the only one that lets you create custom worlds and personalized avatar rigs using Unity.
VRChat is built with Unity, and you can use Unity to make custom worlds and avatars. If you haven't tried it, download a copy of the client from Steam (http://store.steampowered.com/app/438100/VRChat/) and play around with it.
As of this writing, VRChat requires the older Unity 5.6.3p1 version. (Download at https://unity3d.com/unity/qa/patch-releases/5.6.3p1.) Copy your project into a new folder before attempting to open it in an older version of Unity. You may get warnings, but go ahead. They...