which book should I study

Check my comment on Soviet Chess Primer here...
Good Chess Books for Beginners and Beyond...
https://www.chess.com/blog/RussBell/good-chess-books-for-beginners-and-beyond

I'd read the bits in both that you understand or feel that you almost understand, and not try to read the whole book in either case.
My understanding is that both of these books start off easy and then progress (in the case of the soviet primer up to expert level) rapidly. I never really understand who such books are aimed at, other than some supremely gifted person who has never played chess before.
Given the cost of books - which can be had cheaply on eBay, and there are many out-of-copyright books free on-line - and the significant investment of your time that you need to put into studying a chess book, it might be better to choose another from RussBell's list.

If it's of interest there's a debate about the Capablanca book here:
https://www.chess.com/forum/view/chess-equipment/capablanca-book?page=1
The Soviet Chess Primer also gets a mention, as well as a "The Game of Chess" by Tarrasch - in amongst the usual mud-slinging that make these forums so charming.