For a simple, easy to understand overview of git, nothing beats The Git Parable [1]. Every time I talk to someone starting out with Git I recommend they read it first. Once they understand Git through that lens, usually I find the rest falls into place.
This is my go-to video for anyone looking to learn git. It won't teach you the various commands on the command line but it shows you what is actually happening inside git when you perform various actions. It made me transition from "I know how to run these commands to operate git" to "I know what git is doing, so I can reason about the system and adapt to unusual circumstances". Now when someone makes a mistake in my company's git, I am the person people go to for help.
[1] https://www.youtube.com/watch?v=1ffBJ4sVUb4