1)Basics of github:-
https://youtube.com/playlist?list=PL4cUxeGkcC9goXbgTDQ0n_4TBzOO0ocPR

This playlist gives a good insight into basics of github. After learning basics of github it is always better to do some small works/projects on github.You learn much more while applying than while seeing tutorials.

2)Installing linux on your windows pc(dual booting) This is a tough job for a person who is installing linux for the first time.There are lot of tutorials on youtube and google which are having differences in them so it becomes a tedious job to find which is better. Out of many tutorials I saw this one is the best in my opinion.

https://itsfoss.com/install-ubuntu-1404-dual-boot-mode-windows-8-81-uefi/

Make sure you follow exact steps given in this.(if your windows has a bitlock encryption then please remove it as given in the tutorial otherwise it makes life tougher).

Now there is a case you may encounter an "RST ERROR".In this case you can follow the steps in this blog:

https://dev.to/lakshmiwarrier/dual-booting-windows-10-and-ubuntu-20-04-with-rst-issue-fixed-4le8.