Arjen Wiersma has a very nice introductory video on Magit. He covers the basic usage such as staging, committing, creating and checking out branches, and logging. If you’re just coming to Magit, it serves as good way to get oriented.
The video is 18 minutes so you’ll need to schedule a bit of time. Eighteen minutes is long enough to get you going but not so long that you get bogged down in details. Wiersma points to the Magit documentation and recommends that for more details or questions.
Wiersma has several videos available. Most of them involve Clojure related topics but he also has some on Emacs. Be sure to take a look at his channel to see what’s available.