I have more experience with Unity and I'm going to ask you to just Google most of this but... Git LFS is fine. Many shops use Perforce (although I hate it).

I have more experience with Unity and I'm going to ask you to just Google most of this but... Git LFS is fine. Many shops use Perforce (although I hate it). >import photogrammetry assets? Depends what you have. The standard pipeline is to use a tool like Maya or Blender for model work and import into the engine as obj or fbx files. Unreal is supposed to have a pretty good out of the box network setup. Yes every VR platform seems to have an SDK for Unity and Unreal. Shaders and shader dev are a very deep topic that you should google.