You don't have to have a shell at hand to get something out of this book. Still, as with most practical subjects, you'll learn more if you try things out as you go. You shouldn't feel guilty about skipping this section. It will always be here later if you need it.
Not so long ago, it was common for schools and ISPs to hand out shell accounts on big shared systems. People learned the command line as a side effect of reading their e-mail.
That doesn't happen as often now, but in the meanwhile computers have become relatively cheap and free software is abundant. If you're reading this on the web, you can probably get access to a shell. Some options follow.
Check out [tilde.town][tildetown]:
tilde.town is an intentional digital community for making art, socializing, and learning. Unlike many online spaces, users interact with tilde.town through a direct connection instead of a web site. This means using a tool called ssh and other text based tools.
Do you have a single-board computer laying around? Perfect. If you already run the standard Raspbian, Debian on a BeagleBone, or a similar-enough Linux, you don't need much else. I wrote most of this text on a Raspberry Pi, and the example commands should all work there.
A few options: