"He recommends reading the Emacs Manual" is basic and obvious that a lot of people miss it. I try to do it for all software that I use. I don't need to memorize it, but familiarity is helpful.
Even if I can't remember how to do X I know the piece of software I'm using can do X.
It’s very long and dry. I recommend balance it with installing some flashy packages like selectrum, company-mode, and eglot. The wonder created from using incredible packages helps fuel and direct the drudgery of learning the nitty gritty.
Even if I can't remember how to do X I know the piece of software I'm using can do X.