What does a beginner need to learn MongoDB?

Question

Python

Hello! My main questions have already been answered here.
I'm going to start learning Python programming by writing a good messenger right away.
1) Databases I want to choose Mongo. Can you please tell me if there are good tutorials or resources for learning on it? I am extremely grateful.
2) Next, I will use WebSockets. How to teach them?
3) And to the heap, advise on what other technologies do you need knowledge to write a messenger?

Answer 1

1) Official course, free online:
https://university.mongodb.com/courses/M101P/about
2) What is there to learn, there are four methods in total
https://learn.javascript.ru/websockets
The library is better than SockJS
3) Depending on which platform, if for the web then HTML/CSS/JavaScript

Answer 2

MongoDB Little Book Pretty detailed