london
https://www.chess.com/openings you can find all opening and its variantions here
So, which one should I learn ?
You should not learn any of those. You already have some openings you are familiar with.
There are much more important and much more fruitful things to do with your time spent on chess. Tactics and endgames.
Of course, if you really want to spend your time to learn a new opening, sure, go ahead and learn whichever you want. But it won't help you get better at chess.
Your only important task in the opening is to reach a middle-game position in which you feel comfortable and confident.
Whatever sequence of moves gets you there is the right opening for you.
Too many people consider "a new opening" to be a miracle cure.
You keep losing chess chess games? Get a new opening.
Going bald? Get a new opening.
Your dog died? Get a new opening.
Hi ! I'm a beginner at chess. I know Queen Gambit, Italian Game and London system but I want to learn another opening. Which one should I learn ?
Your opening choice should be based on the types of middle games you're comfortable playing. Review your games and find all the games you lost due to the opening. You'll find that will be right around 0%.
I like kings Indian attack. Black’s moves are a possibility.
Kings Indian attack - is it the same as Reti opening?
Hi ! I'm a beginner at chess. I know Queen Gambit, Italian Game and London system but I want to learn another opening. Which one should I learn ?
All of those are white openings so I think you should try to learn something with black. Maybe the caro-kann or the scandinavian, (GothamChess has adviced begginers to play it in the past and he has videos on it.) against e4. Agaist d4 you should probably try to play some kind of copycat system that creates an equal position in the middlegame.
Hi ! I'm a beginner at chess. I know Queen Gambit, Italian Game and London system but I want to learn another opening. Which one should I learn ?