Elo aimed for Capablanca's Chess fundamentals

@1
"What is the Chess fundamentals book by Capablanca elo range"
++ None, elo did not exist when he wrote it.
"I'm 781 Elo rapid and I know the basic tactics and elements like space and initiative"
++ Study the book.
"Should I read it?" ++ Not read, but study, preferably with 2 chess sets, one for the main line and one for variations.
"it just doesn't seem to teach anything" ++ It teaches everything.
"In the first concept it teaches, king and rook vs king, it just gives a sequence that ends in mate the fastest way, without really explaining a general concept in what to do."
++ You have to practice yourself.
"reading the two hundred pages of it" ++ It has only 60 pages.