Although it’s far from the focus of the course, we’ll be using the command-line in class, and you’ll be better off if you’re not trying to learn it from scratch alongside React.
Command Line Power User series by Wes Bos is an excellent introduction to the *NIX style command line. This free course requires an email sign up, but all the videos are on YouTube if you want to hunt for them. (Wes’s email list is pretty good though.)