How to deal with the issue of authorization / authentication and registration?

Question

Yii

It so happened that I started working with php immediately with the yii2 framework. When I create a project on this framework and implement authorization and registration according to a blank in Yii2, then what and how to do is clear, but due to the fact that I did not initially program in pure php, as I understand it, I lost a lot of essence.
What book or resources can you catch up with, such as where an example of creating a registration is described, what are tokens, and so on.

Answer 1

Goodnight.
All links on yii2, the first two are from the developers.
Documentation
Recipes
Authorization

Answer 2

PHP documentation should suffice.

Answer 3

Internet and Wikipedia if theory
or stackoverflow is stupid in practice