How do I improve on chess as a beginner?

Here is a recent game.

Did moving your knight leave anything of yours open to attack?

You were quickly lost in the opening.

Going through the games afterward can help you spot the big blunders you have made.

Look mostly at the games you lost will help you the most.

Learning to spot the blunders before you make the moves is what you are hoping to learn.

Good luck.

Hi

I am rated over 2400 online (https://www.chess.com/member/ppandachess). I created a free course that will teach you a training plan to improve, including how to work on your middlegame play. Feel free to check it out: https://www.panda-chess.com/daily-improvement-plan

Improving Your Chess - Resources for Beginners and Beyond

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

Learn and apply the most important principles of chess. - (core of my teaching)
Always blunder-check your moves.
Solve tactics in the right way.
Analyze your games.
Study games of strong players.
Learn how to be more psychologically resilient.
Work on your time management skills.
Get a coach if you can.

The best piece of advice, in general, is this: Pay attention.

When it's your turn to move, look around and ask yourself...

1. Are there any checks? 
1.1 If yes, do any of them help you?
1.11 If yes, do it.
1.12 If no, do not play a check.

2. Are there any threats you can make?
2.1 If yes, do any of them help you?
2.11 If yes, do it.
2.12 If no, do not play that move.

3. Find a piece of yours that sucks. One that's in a bad place and not doing anything at all. Can you make it better?
3.1 If yes, find out how.

If you answer "no" to all three of these questions when thinking of a move, then you are in zugzwang and should probably resign, especially if the game has been going for a while.

When your opponent has moved:
1. Analyze it. What are they trying to do?
2. Did they hang a piece?
2.1 If yes, figure out if it's a blunder or a clever sacrifice.

Your opponent wants to win just as much as you do. You have to give it your all to outsmart them and punish their errors. The problem is, that's also what they're trying to do, so that means you have to be careful as well.

Other miscellaneous tips include:

- Think before you move. Look at the move you want to do very carefully to see what might happen. If you don't like what you see, then don't do it.

- Always assume that your opponent will play the best move. Of course, we're all only human, so there are going to be mistakes. But if you only play reckless moves in the hopes that a mistake will occur, you're going to lose a lot of games. Play the objectively best moves; in the event that your opponent makes a mistake, jump on it. You can't force a mistake, but you can punish it.

- When it's your turn, look for sacrifices you can make. This sounds silly, but it's gotten me quite a few brilliant moves. When looking at sacrifices, you'll often find that most (if not all) of them are blunders. Occasionally, however, you may look at one and realize it's a great idea. So, go for it!

- Learn to recognize if a piece is "good" or "bad." A piece is good if it creates a lot of problems for your opponent. On the other hand, if it's not doing much of anything, it's bad. Even though certain pieces may be of equal value, you should evaluate their "quality" on the board before thinking about trading them. Trading a knight that's barely doing anything for your opponent's bishop that's preventing you from castling is a great idea; trading your bishop that's eyeing the king for a knight that hasn't even moved is a bad idea. In other words: "Equal" trades, despite their name, are actually not inherently equal.

I'm sure there's more, but all of these have worked great for me so far. Two months ago I was just about to fall below 500, and now I've been climbing pretty quickly (though I seem to have stagnated again as of late).

The above advice is all excellent! I've looked at a couple of your games, and I'd like to throw in my 2 cents. 
1. Be very careful with pawn moves. They should be moved only with a strong purpose in mind because once they're out there, they can never come back. Plus, moving them too early leaves your king more vulnerable.
2. Use ALL your pieces. You tend to move one or two pieces several times while the others sit on the bench waiting to be called into the game.
3. After EVERY move by your opponent, reevaluate the position. Have they attacked you in any way? Are they making a threat? Have they left a piece open for you to capture?
4. BEFORE every move you make, look to see if it's going to land on a square where it can be captured. Make sure your king is safe (see early pawn moves above).
5. Play LOTS AND LOTS of games--none faster than 10/5. After every win and loss, go back over the game and really look at the moves you and your opponent made. In the two games I looked at, both of you appear to have been playing blindfolded at times. Pieces were just sitting there waiting to be captured--and THEN THEY WEREN'T CAPTURED!
6. Finally, you say that, as a beginner, you really can't tell what went wrong in the game. Well, of course you can't--yet. This comes with lots of experience, and there's no substitute for it. Believe me, if you play a couple of games a day on chess.com, if you do at least 10 tactics puzzles a day, if you play over and carefully look at as many master games as you can, you will come back a year from now and look at these early games and say, "Who thehell was that idiot pretending to be me?"
7. OK, finally finally: I don't know what level of membership you have, but some of chess.com's best features cost money. If you're strapped (and who isn't), consider lichess.org for totally free play for all features. And consider chessgames.com for the finest collection of master games to be found anywhere--also free.