What to play after 1.d4 for beginners.

Hello.

I am a very beginner player.

I don't know what know hat to play against 1.d4. (Queens gambit or London System)

I know that there are many options ( Dutch, KID, Benoni ) but I need a low theory opening.

I use in my games the London System as white and Caro-Kann as black. With mixed results. 

I also wish to change Caro-Kann for something easier.

Yo! Well, I would recommend the King's Indian defence. Gothamchess has a great video on it but essentially you play Nf6 against d4. You can play this against e4 too but then you should play d6 first to defend your knight.  If you don't then it's called the Alekhine's defence. The Alekhine's defence isn't that good in theory but the idea is to trick the opponent into overextending by attacking the knight with pawns. I imagine it could work for a beginner.

The answers in this thread are compete nonsense.

A beginner level player should not think about openings at all. You should google "opening principles" and use those, that's more than enough. If you want to get better at chess, this is the way:

https://www.chess.com/puzzles

https://www.chess.com/lessons/skill-level/beginner

none of the comments so far were useful imo, you need to get down and study a defense! Queen's Gambit Declined is very simple albeit a little passive but 9 out of 10 games you will face the London anyways so I'd say that's a priority

At our level, openings don't matter - they are not what decide the results of our games, and their study doesn't lead to any improvement. 

https://www.youtube.com/watch?v=WPIMRMl0guA

ConfusedGhoul - your advice can prove to be quite damaging and detrimental to the potential for improvement of many beginners.  

Against 1.d4, I try to play into a Semi-Slav but most times, it doesn't work when they deviate from the mainline. I recommend playing ...d5 and ...Nf6 and develop your pieces. If you are curious about it and don't mind learning just a little theory, I have a link to a study here. Against the London, most players around your rating play the London without thinking so I will show you in a trap in the London, although it is dubious so don't try it against high opposition

Against 1.e4, I love the French Defense. Most players at your level are not going to be as comfortable with it as someone who plays just the French. I have a study about the French that covers everything except the Classical Variation (no one plays it even at 1500) which you can find here. Check it out if you are interested and/or face a different variation that is covered in my study.
 

BoratSagdiev the QGD is a very Classical openings that teach people to play principled chess, are you saying a lower rated player can't study a simple Defense? I actually think he can do it and you can't always live by opening principles. I also disagree with your statement: I own many Chessable courses and S&S on openings and besides opening preparation I also get insights of how a GM evaluates a position, why he thinks a given side is better and what he can do to increase his advantage

QGD is a good opening. If anyone is interested in playing against it, I highly recommend my chess study here which will cover anything you need to know to play the Queen's Gambit

EKAFC the Classical French is what I usually play against the French along with the Tarrasch but I agree with you as many players like the Advance variation (they usually blunder d4 at some point) or the dull Exchange

At your level you should not be concerning yourself with studying openings. You should just play your openings based on general opening principles. These are: get control over the center (white wants to get e4 and d4, black wants to prevent this), develop your pieces (every piece should only move once) and get your king safe by castling. After 1. d4 the easiest way to do this is with 1. ...d5. If white plays 2. c4, you don't take the pawn (that would allow e4 for white and we just don't want to give that away at the beginner's level), but you play either c6 or e6 to defend it. After that you can just develop your pieces and get your king safe. No more study is needed.

No, openings are always important. The king's Indian is simple enough for a beginner.

No it's not. The King's Indian is an advanced opening. Black's giving up the center and needs to know what he's doing or be seriously worse.

I'm often shocked with the stubbornness of some people - you have a titled player (and other high rated players in the thread) giving incredibly valuable advice, and you still find the energy to argue? 

Yep. These people are so highly rated that they don't know how games are at a lower rating.

I would not recommend KID for beginners. As the CM in this thread stated, its advanced. Plus it requires sharp play like the Sicilian defense.