A great way to learn the basics. It’ll be old, but that’s ok. It’s going to cover all the shell basics and then more. It’s still going to be useful, it’ll cost you pennies, you’ll be able to dip into it when you want, and you’ll be giving to a good cause.
I did SEC+ entirely from book, i kinda prefer books tbh. Nothing like a slapping a manual on a table and saying RTFM.