The first video lecture [1] is titled "Introduction to Linux", yet, ironically, the instructor conducts the entire lecture using macOS. I guess the main purpose of this course is to teach uninitiated kids a thing or two about the *nix CLI, but for some reason the instructor has decided to call it the "Linux CLI". He also teaches some terrible shell scripting practices [2] such as parsing the output of ls [3] and not quoting variables.
[1] https://www.youtube.com/watch?v=hTHAe-m56Vw
[2] https://www.youtube.com/watch?v=rOxJW7PtA5s&t=169s
[3] http://mywiki.wooledge.org/ParsingLs