It depends on the level. The big early gains to get to let's say 2200+ were basically exclusively tactics. You really have to get your board vision to quite a decent level before the other parts of learning really start kicking in, and that's going to take thousands of hours of tactics. An important part of tactics is to ensure you actually work out the entire line - instead of just playing the obvious tactical idea, like Bxh7 or whatever, and going from there.
This was paired with 'analyzing' games of classical master (Alekhine, Capablanca, and so on) and then comparing my analysis against master analysis in plain English. Older books like Alekhine's best games books, or the various master vs amateur books (Euwe's is amazing) are a great resource here. Chessbase also now has a feature 'replay training' built in that would be really good for this. Load up a game, click on replay training, and you can basically play guess-the-move with automatic feedback in terms of how your move compares to the game as played (without revealing that move), as well as the top computer move.
It's also important to start appreciating typical piece repositioning ideas - for instance the rook lift is something that isn't very intuitive at first but radically reshapes many positions. If that rook on a1 heads to a3 and then on over to g3, a quiet Italian position can go from uninspiring to an unstoppable kingside attack really fast. The same is true of all the other pieces - for instance in the typical Najdorf structure with pawns on e5 and d6, knights on f6/d7, and bishop on e7 - if that bishop can go from e7 to e.g. b6 (so long as d6 remains solid enough), it can suddenly become a monster piece.
A key is to avoid excessive opening study until much later. It's a trap because you can spend an infinite amount of time learning openings, and you will get some wins without ever even leaving book, which feels pretty dang rewarding, but in the longrun it will stunt your growth. I remember at one point, sometime around 1800, delusionally thinking that the main difference between me and Kasparov was his encyclopedic opening knowledge. A quick glance at Hikaru doing puzzle rush will emphasize that's not quite right, of course this was long before GMs streaming was a thing! On the equal but opposite side, I also would recommend avoiding 'system' openings as a means of not having to worry about openings because the ideas and plans you see and learn in classical openings help improve your understanding much more than seeing an e.g. Colle each and every game.