Although the React VR library is simple, to really learn what it's all about, you need to learn a lot of syntax. You could skim it, but there is a danger to knowing a little bit without being somewhat familiar with everything.
"A little Learning is a dang'rous Thing; Drink deep, or taste not the Pierian Spring: There shallow Draughts intoxicate the Brain, And drinking largely sobers us again."
-An Essay on Criticism, by Alexander Pope.
You may be thinking "OK, but where's all the VR stuff? You know, tables, chairs, lamps, people ... and so forth." These are going to be a deep drink indeed--there are quite a number of components.
The best reference is the online documentation, although they can be a tad sparse at times. Remember that the online documentation is live, meaning you can file an issue or even modify it, if you see a typo or need clarification.
I highly recommend that you view the next section as a reference section. Of course, you could need help going...