Beginner stages

I started playing about a month ago. My rating bounced all over the place, but soon settled down the the mid 700s. Mostly I lost games in the opening, falling for one trap after another.

Then I learned how to protect myself in the opening and my rating crept up to the 800s. Mostly I lost in the middle game to confusing exchanges and silly blunders.

Then I learned how to protect myself in the middle game and my rating started creeping up to the high 800s and low 900s. Now I'm getting slaughtered in rook+pawn end games.

I don't seem to be having any luck learning how to handle end games. Can anyone suggest a good book or method of study for end games? I'm not going to get a coach simply because I'm an old, retired amateur, learning to play just for fun, but I sure would like to get myself up into the 1200-1400 range eventually.

This might be of some use to you:

https://www.chess.com/blog/nklristic/how-to-approach-the-endgame-first-steps-to-chess-improvement

As for where to study, there is a lot of content on Youtube for basic stuff at least.

As for books, many people say that Silman's endgame manual and 100 endgames you must know by Jesus De la Villa are great. There are other ones but something like Dvoretsky is far too advanced (even for intermediate players).

But anyway, try to master basic checkmates, basic maneuvers like opposition and basic positions like Philidor position and Lucena... Learn king and pawn endgames, those are rather basic but are really handy. If you read that link I've given you, you will see that there are a lot of people rated 1 300 and perhaps higher that don't know how to make use of those positions.

As for Youtube chanels I've mentioned, you can find them here:

https://www.chess.com/blog/nklristic/the-beginners-tale-first-steps-to-chess-improvement

Apart from that, you can find there some tips that helped me improve in this last year.

In any case, good luck on your chess improvement.