What should I develop as a 1300?

I've recently moved from lichess and is currently stuck at the 1300s in rapid. Other than trying not to hang pieces or blunder, what should 1300 generally improve at? I would love to learn openings or endgames but I dont think that opening matter a lot at my level.

at this point of the game you should really start working on improving your middle game and figuring out how to improve your pieces/find the best plan in each position. This kind of stuff is the backbone of chess middlegame and is nessacery to improve.

Everyone learns differently, so I agree the middlegame is where the majority of improvement will come from; however, there are other factors to consider. If you were only allowed to take one class in school, it would be more horrific than it already is. Studying openings and endgames are also very important for improvement and can keep you motivated to continue to improve.

The three phases of chess are not mutually exclusive. Improvement in one phase will carry over and help with the other phases. Understanding endgames will help you select moves that will lead to a winning endgame. Likewise, basic understanding of openings will help you to avoid blunders that make it very difficult to survive the middlegame.

So spend more of your time on tactics and middlegame strategy, but you do not need to neglect openings and endgames. At first, study basic principles and as you gain greater understanding, you will be better prepared for intermediate and advanced concepts.

Improving Your Chess - Resources for Beginners and Beyond...

https://www.chess.com/blog/RussBell/improving-your-chess-resources-for-beginners-and-beyond

Use this white repertoire against najdorf defence. This is my friend youtube channel Chess Learning. Here is the link to that game against the najdorf. >>> https://www.youtube.com/watch?v=1RVoc1GkHKY

"Other than trying not to hang pieces or blunder, what should 1300 generally improve at?"
++ Most important is to check your moves so as not to blunder.
Then next step is tactics. Solve tactics puzzles. Analyse your lost games.
"I would love to learn openings or endgames" ++ Endgames study is good.
"I dont think that opening matter a lot at my level." ++ That is right. Openings do not matter at all.

Some good advice

Lessons, videos

 

Good luck 

I think a little bit of opening theory would actually help you get a position you enjoy playing in the middle game... do not worry too much about memorizing moves and don't go too too deep into the variants, but try to understand the ideas, plans, where the pieces usually go, common themes, possible tactical motifs to keep an eye on, piece maneuvering, etc...

Other than that tactics tactics tactics

And some endgame study won't hurt either

Logical intuition is probably best. Being able to find a good plan in most positions is a much more valuable skill than lengthy calculation. This way you waste less time on frivolous calculation adventures that won’t give any returns and focus only on the good stuff, and chances are you’ll cut down on blunders and make better moves automatically.

Try to develop all your pieces depending on what your opponent allows, preferably develop knights before bishops and minor pieces before rooks and queens lol

I do have a youtube channel.It is on my profile and I do promote my own channel.

yes, and please dont promote you and your friends youtube channel its annoying.

based

How does one develop such a thing?