WebVR Training Sites
Reality Check
First, remember that it isn’t new. 3D Stereo Imaging has been around 150 years, since the beginning of photography itself!
Here’s one for AR
https://yourstory.com/2018/01/history-of-augmented-reality/
Learn WebVR
27 WebVR projects with source code, Source code can be used for both personal and commercial use.
Tutorials for VR