For real. Hacknet uses commands that work like that in the usual Linux terminals. Including the auto complete feature. At the very least you will learn the basics from that game. As for if you should start to play it. Well the question is if you enjoy a puzzle game with a story that is hacking themed using actual terminal commands to do stuff. If that sounds like fun the go for it.

Ah hacknet. Teaching people Linux terminal in a fun way without them even noticing.

Never stopped using cash. It works, is less trackable and most importantly is accepted for exchange of goods even outside of your typical store front. Say when buying hay or straw for horses and paying then and there.