The book "Pro Git" is a good starting point

https://git-scm.com/book/en/v2

you can ignore the bitbucket stuff and jump straight to git beginners, but other than that, the atlassian tutorials are one of the best explainers and guides I've come across, they make sure you're learning the fundamentals instead of just giving you the commands https://www.atlassian.com/git/tutorials

Id recommend spending some time thinking about real world scenarios as well...

eg https://www.freecodecamp.org/news/how-to-use-git-and-github-in-a-team-like-a-pro/

Also,

- If you fuck up a Git repository its one of the worst things to go through as a dev learning GIT in my experience. Its so annoying.

- Go slow, understand the commands you are using and if its really important (client work for eg) and you aren't sure make a quick copy. Even though that contradicts the reason why you'd use GIT in the first place! I did it while I was learning Git and it saved me some time.

- I found using Git on command line to be useful in the beginning but moving to a program is popular even though I still like using the command line tbh.

Happy coding:)