@semordnilap I would focus more on higher level concepts, such as why there are central repos for distros, what free and open source software is all about, and a brief (1-2 minute) talk that most software you'd want to use on Windows or Mac are either on Linux or there are equivalents.
I wouldn't focus on file management via CLI, other than to say that its there (and its fairly simple). I would talk about pipes a lot though, and some cool tricks you can do with it.