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.
A game I only bought because someone else wanted to play that together on a private LAN party. That person then announced that they couldn’t show up. And since I was terribly uninterested in playing that game on my own and only bought it for just that occasion, I refunded it after that news.