The complete Chess Course
Chess Books

Chess Fundamentals by Jose Raul Capablanca if thats not enough for you then I'd also recommend Chess Structures A Grandmasters guide by Maurico Flores Rios

José Capablanca, Chess Fundamentals and at least one of
Also, you might toss Rozman’s book into the circular file.

Chess Fundamentals by Jose Raul Capablanca if thats not enough for you then I'd also recommend Chess Structures A Grandmasters guide by Maurico Flores Rios
Chess Structures is very good, but is not for beginners. Read it when you are over 1700.
If you take your chess to the next level it will not happen with one book. You will need to study openings, middle games and end games. especially rook and pawn and pawn end games. Also get "My System" by Nimzovich. I read it twice and my rating increase greatly over 2 years.
How about for a 1300 who’s shooting for a low advanced level in the next couple years?
There is no best and what you need depends o your strengths and weaknesses. I can tell you what I do-others will too- and you can pick what makes sense to you.
Currently, I do tactics online. But early on, 'The Art of Checkmate' was eye opening. Chess got a lot more fun after that book!
Most of the time, I'm working thru 3 books: One is a book of annotated GM games. Early on, I worked thru the books of Fischer, Keres, Botvinnik. Since then Chernev's book 'Capablanca's greatest endings' and Smyslov's book. They are all excellent-pick one and go!
The second book I work thru is one on middlegame strategy. Early on Pachman's book--it is a classic for a reason. Currently, one of Gelfand's.
After going thru a few games in the first two, the board is empty so I do a few pages in an endgame book- either one on fundamental/theoretical or on complex/strategic depending on what happened in the last ending I played. The problem with endings is not learning them. It is retaining and using what you learn. If I study what I've just played it seems to stick better.
I find that working thru 3 means it doesnt get boring and feel like studying Latin grammar. And that I get a lot from each of those 3 types of books.
Bill

How about for a 1300 who’s shooting for a low advanced level in the next couple years?
Get all three of the checkmate books I posted. Also study Jeremy Silman, How to Reasses Your Chess. Play through all of Paul Morphy’s games. That won’t be enough, but it will set you on the right course.

I’m generally a long game player who plays conservatively and plays for winning endgames or for my opponent to blunder, but most of my losses are when I mess up or overlook something myself. How can I 1) minimize these mistakes and 2) get better at attacking and defending, particularly the former? I assume the checkmate books would help with that. Is a lot of what I should be doing simply tactics, capitalizing on opponent mistakes?

I’m generally a long game player who plays conservatively and plays for winning endgames or for my opponent to blunder, but most of my losses are when I mess up or overlook something myself. How can I 1) minimize these mistakes and 2) get better at attacking and defending, particularly the former? I assume the checkmate books would help with that. Is a lot of what I should be doing simply tactics, capitalizing on opponent mistakes?
For this i recommend "How To Reasses Your Chess" by Jeremy Silman

If you take your chess to the next level it will not happen with one book. You will need to study openings, middle games and end games. especially rook and pawn and pawn end games. Also get "My System" by Nimzovich. I read it twice and my rating increase greatly over 2 years.
agreed, everyone needs to read it eventually so you might as well get it now
I read My System twenty years ago, but superficially. Three weeks ago, I acquired a copy of the newer translation that has My System, Chess Praxis, and additional texts. It also restores passages that were deemed unsuitable for sensitive readers when the books were originally translated.
I’ve been reading it more carefully this time. It is probably a coincidence, but my rapid and blitz ratings have both risen over the past two weeks.
I am looking for a new chess book. I am 1000 elo, already have GothamChess’s book and I am looking for one to take my chess to the next level. Any suggestions?