[stfwn]

What kind of diagnoses are you interested in learning about? This may be too rudimentary, but I found ‘The Linux Command Line’ a good book to build up skills and knowledge.

Also I would say: don’t try to force it. People write a lot about ricing their Gentoo installs, which tiling window managers use the least RAM and which plugins they use with Neovim. This makes using the terminal effectively seem like a big thing.

But the terminal is exactly not that — all proxies are removed and you just use it for what you want to do, nothing more. Just start by using grep on a text file instead of opening that text file up in your editor.