How to properly organize the architecture of a web application?

Question

Angular

I am developing a web application.
Architecture:
* Angular client
* Static web server for passing the client part (node, express)
* API (node, express, mongodb)
The following questions arise:
* I plan to make two APIs.
The first one is for authentication. What protocol to use? To make it easy to add third-party authentication in the future, for example, from VK and Google
Second for accessing resources (via closed, open routes)
* How to store a user in the database with third-party authentication?
If local, then it is clear that the scheme will have a login, password, mail, etc.
What if third-party authentication occurs?
What to store? what will be the scheme?