Sicilian Defence or Caro-Kann also help with Queen's pawn opening I know and play the Sicilian defense. Specifically, I mix it with the Hyper Accelerated Dragon with the kingside rook pawn movement akin to the Najdorf. I am also learning the Caro-Kann, in which most of my opponents play the advanced variation or I start the exchange variation. But most of my opponents never play the mainline past the first move, so I just employ basic chess tactics such as central control and development.
Which opening should I learn the best? I learned the Dragon to the point where I can consequently out develop my opponents early with the Hyper Accelerated Dragon, but I have also heard that the Caro-Kann is good enough to know.
Also, I know the Queen's and King Indian Defenses enough to counter any 1. d4 players. Although not many people do it, I still think it's worth it. Should I add it to my arsenal, for Black at least? For White, I used to play the Queen's Gambit, but now I play the English.
For a more meaningful answer, it'd be a great idea to know what your current skill level is. That being said:
Knowing an opening is not about knowing &quot;what's on the book&quot;. If you can't find the correct response when your opponent deviates, then to all practical effects it's as if you didn't know anything the opening, no matter how depth into the mainline you've studied. Mainlines also change over time and from author to author. Study the key strategical ideas of the opening, not concrete variations.
Also consider that at lower levels, it's not really worth studying the opening, since:

The difference between playing well in the opening or not is not that big and there's a lot of time to catch up during the rest of the game if you are worse.
Studying the opening is harder as a beginner because you need to memorize more. GMs can remember hundreds of 20-move deep lines because they only have to remember a few critical points, the rest comes intuitively to them.

When choosing between Hyper-accelerated Dragon and Caro-Kann, I personally prefer the former because as you'll have to know a fair amount of theory for both, you'll better play the opening that puts your opponent into bigger trouble if he messes up. But there are deifnitely arguments for the Caro-Kann and it's hard to tell what suits you best without knowing your skill level or &quot;playing style&quot;.
The Queen's Indian is a great opening that can teach you a lot about chess. If you already know about it, there's no reason not to include it in your repertoire