My openings sucks. How should I improve?

Youre a 500 rapid player that is losing in 4 moves:

https://www.chess.com/game/live/26712574845?username=lexlibman

Openings are the last thing that is causing you to lose. 

French Defense

Use opening principles.  At your level openings do not decide your games, and NO ONE knows any opening theory, so instead of memorizing moves.  Learn and understand the "why" behind the moves. 

This is what you should be working on:

Opening Principles:

1. Control the center squares – d4-e4-d5-e5
2. Develop your minor pieces toward the center – piece activity is the key
3. Castle
4. Connect your rooks

Tactics...tactics...tactics...

The objective of development is about improving the value of your pieces by increasing the importance of their roles. Well-developed pieces have more fire-power than undeveloped pieces and they do more in helping you gain control.

Now we will look at 5 practical things you can do to help you achieve your development objective.

They are:

1. Give priority to your least active pieces.

• Which piece needs to be developed (which piece is the least active)
• Where should it go (where can its role be maximized)

2. Exchange your least active pieces for your opponent’s active pieces.
3. Restrict the development of your opponent’s pieces.
4. Neutralize your opponent’s best piece.
5. Secure strong squares for your pieces.

Don’t help your opponent develop.

There are 2 common mistakes whereby you will simply be helping your opponent to develop:

1. Making a weak threat that can easily be blocked
2. Making an exchange that helps your opponent to develop a piece

Pre Move Checklist:

1. Make sure all your pieces are safe.
2. Look for forcing moves: Checks, captures, threats. You want to look at ALL forcing moves (even the bad ones) as this will force you look at, and see the entire board.
3. If there are no forcing moves, you then want to remove any of your opponent’s pieces from your side of the board.
4. If your opponent doesn’t have any of his pieces on your side of the board, then you want to improve the position of your least active piece.
5. After each move by your opponent, ask yourself: "What is my opponent trying to do?"

White: London System.

Black:

Against e4 - French Defense. - Easy for you, hard for opponent.

Against d4 - I guess Nimzo-Indian. best by top players, there's a reason to it. I don't see it though.

GM Aman Hambleton has a series on beginner principles on YouTube.  

If you want openings, Colle for white and anti-fried liver attack for black.  Colle is safe, but aggressive and can go from basic five moves (includes castling) to 12 move or so formations.  While playing black, chances are you will face the Fried Liver Attack so knowing the anti version can get you castled quickly and at least surviving the middle and end game. 

Stick with one opening and let Stockfish show your failures and proper responses.

Before offering ridiculous advice.  Please check the OP's ratings and offer advice based on that. 

Thanks Bacon. That's a great response.

Learn safe openings only. Don't bother with suicidal gambits. Ignore them

Don't bother learning openings until you know opening principles.

It'd be highly worth investing 8 minutes of your time to check out a video like:  Chess Basics: Opening Principles

Also:

10 Chess Tips Every Beginner Should Know (9-1/2 minutes, Botez)

And some nice blogs devoted to principles:

https://www.chess.com/blog/KeSetoKaiba/opening-principles-again

https://www.chess.com/blog/nklristic/surviving-the-opening-first-steps-to-chess-improvement

Nice post from llama42 about CCT

https://www.chess.com/forum/view/for-beginners/the-most-important-concept-for-all-beginners

Pardon me being short with my initial response.  Its just that this question is asked all the time.

I already lost many times due dont know thw defense for SHEPHERD'S MATE

1st move: Pawn e.4

2nd: knight f.3

3rd. Pawn d.4

Btw this is For white.

For Black 1st move would be Pawn e.5 if the opponent starts with kings pawn.

1st: Pawn e.5

2nd: Knight c.6

The rest will depend on the opponent but if white plays like I recommend then

3rd. Pawn takes d.4

There is more to these openings but I thought id keep it short. Remember that most people won't play exactly the same so you have to be careful that these moves won't always apply.

Try to use the Modern defence.

I think AiChessCoach.net is a great resource for players aiming to strengthen their chess openings. It's a free tool that can analyze your most recent 200, 500, or even 1000 games from sites like Lichess and Chess.com. It offers personalized opening recommendations and highlights recurring mistakes, helping you focus on areas where you can improve. Definitely worth a look if you want insights tailored to your own games.