When I got into Linux I read every physical book I could. Physical books on a subject tend to be written to have chapters that cover whole material. When you try and learn from multipe ebooks you randomly found online you end up cherry picking bits and pieces and never actually read every chapter, so you miss fundamentals.
Maybe you would benefit by reading a PAPER copy of a book about Linux and the especially command line. Linux is a very command line oriented system so maybe trying to tackle some of the struggles head on will help you unlock apt any other tools.