I’ll add that if you can’t find it on libgen, or if you’re looking for comics and manga ie things that might not be on there, FMHY is a great thing to google ;) includes audiobooks if you’d prefer that to reading. Includes direct downloads as well as torrents.
That said, depending on what you want to learn, there may be a youtube video on it. There’s tons on youtube for certain subjects like video editing or coding if that’s what you’re interested in.
Edit to add: if you’d rather buy a physical copy, ebay and AbeBooks are great sources.
I just bought Subnautica and Cities Skylines, so I’m looking forward to playing them both.