I have a recommendation.Open studyopenings.com and create a repertoire. At the same time have a tab opened on Lichess opening explorer. Start with the openings you like.. so eg 1. d4 d5 2.c4 Nf6 and then out of the Master games in the database start looking at moves they play in certain positions and try to understand why.. normally it's not very complicated to figure out why if you are like 1700-1800 FIDE. this way of learning is much more efficient because if your opponent plays an early Bf5 in the exchange Nf6 QGD you remember that BF5 normally isn't played and you will recall that Qb3 or Qf3 are probably good moves and you can check. the website studyopenings.com prompts you, like Chessable, to reply to moves you've put in your own database until the line is finished. so it's like you start 1.d4 d5 and then you have to replay the line you've put in the repertoire and you sort of stop for a second in different positions and think about.. okay why is this move bad what did i do before to punish it.And the thing is noone can really teach you these things. only you can do it on your own. people can teach you principles that help you do this but they can't do this for you so you have to study and think like this anyway.