help a newbie to reach 1500

The first thing I would recommend is to play longer time controls. I would recommend 15|10 time control. I looked through your last two loses, and it looked like you lost because you got too low on time, and had to move fast. This lead to blunders, or losing on time. Based on your puzzle rating I would recommend continuing doing puzzles. You will probably need to get it to around the 2500 rating to get to 1500. You will also need to learn more about imbalances especially the bishop, and knight imbalances. Knowing how to navigate those situations is critical for 1500s. You will also need to work on piece coordination more, and learn how to attack and defend. You may know some of that, but you will have to get better at to get where you want to. For endgames you will need to learn more about king and pawn endgames. You will also need to learn some about knights and bishop endgames (the basics), and you learn need to start learning about rook endgames also. When it comes to openings you can start learning some theory, but really on the variations that you face regularly. This list is not meant to be an exhaustive list of what to learn, but will hopefully guide in some things to work on in general.

As far as the consistency goes what you are experiencing will happen as you are learning, and getting better. You will try to incorporate something new, and miss apply is at times. With experience you will learn when to apply it, and when not to. This will also help with you recognizing what your plans should be faster than before. All of which will help you get better.

Here is some resources to help you get better (Chess Vibes Channel also a lot of other videos that can help you also):

Chess Vibes strategy/tactics playlist

Chess Vibes Endgame Playlist

Learn and apply the most important principles of chess.
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.

This is just a list of truisms... "play good moves, don't play bad moves, it's better to win than to lose." Sure, but none of that helps a person get better.

Avoid blunders

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

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

I honestly ywouldnt know without looking at your games but sometimes longer time controls helps sometimes it doesn't it depends on the person I would recommend reviewing your games and trying to figure out exactly why and how you ldot ,did you lose to a one move tactic like a free e piece,did you tunnel vision on a attack that didn't work ,did you forget to take your opponents free knight when you where winning ,did you convert incorectly,was it time pressure if so do I need to play faster than my opponent so they get pressured instead ? ,did you lose because of bad endgame conversion ,etc did you win but did you have bad conversion ,did you miss simple tactics but your opponent mad emore mistakes ha t cost them the game ,or did I just play a good game ?

You need to analyze what you lost ro how you won and improve off or that or just get really good intuition base off the amount of games you play ,or both

Sometimes asking yourself what is my opponents threat is very useful and looking at checks,captors ,attacks is always good

Btw try to focus on endgames and middgame theory and just follow basic opening principles like develop your pieces (preferably knights first by not always ) honestly at a certain point owing opening principles inst always useful you have to be creative in countering your opponent movsssometimes you have to find weird moves (only if they are good )

You sorta have to work smart +hard to get really good at chess

Just studying won't help and "analyzing" that can only get you so far but neither can just grinding endlessly without learning anything (,tbh that does work for some people ex: Tyler one )

Realy the best way to improve is try to figure out how and why you are making your mistakes and figuring out how you learn best asking other people might help but they don't always give perfect advice and since some people learn differently even good advice sometimes isn't helpful

@1

"how *exactly* to improve my chess skill" ++ Most important is blunder checking. Think about your move, decide. Do not play your intended move, but imagine it played on the board. Now check it does not hang any piece or pawn or does not run into checkmate. Only then play it.

"goal to reach 1500 by the end of this year" ++ A modest goal.

Not really 1500s blunder all the time lol and can typically hold in worse positions but yes try to think of what your opponent will do if you play a move

Winning in worse positions is highly underrated you will almost always blunder in a game so why not make the most of it though at least make sure your queen isn't in the line or sight and free for a taking by a knight (just make sure you aren't making any obvious blunders )