VR for project

Unity Engine
1

So i have a first person game…
Now i want to enable that game to be playable on both orift/gearvr and pc/android devices…

  1. how do i enable my game for playable in VR…

  2. do i have to make a seperate version for VR or both versions can be in a single app??

  3. how is a first person controlled in VR… I mean you can rotate cam by moving your head but how to move forward or backward??

2

Really?? No reply ??

I found out about the first 2 questions…
But 3rd question is still a mystery…

how is a first person controlled in VR… I mean you can rotate cam by moving your head but how to move forward or backward??