I picked up chess again in early August after decades away. As a teenager I’d mostly played very tactical and high memorization openings. High memorization wasn’t going to be a thing coming back, so I looked for an easy to memorize opening repertoire to get started again. I landed on A Simple Chess Opening Repertoire for White by Sam Collins.

Overall I think it’s a good book to get started. One “problem” I had with it is that it has a ton of subvariations, and they’re not at all well separated from the main lines. I spent part the better part of a weekend highlighting the main lines vs the other stuff. With that done, I fed the all of the main lines to a depth of 5-8 moves into Chessbook.com, which has a spaced repetition training feature. At those short lengths the entire repertoire fit into Chessbook without hitting the move-limit paywall. It made for a good crash course on openings. It got me out the door and into middlegames so that I could just play chess.
I’ve gotten away from the book because many of the openings are based around creating an Isolated Queen Pawn for White, and I’ve discovered I now prefer to play a different way.
What I’ve been going for is asymmetrical closed or semi-closed positions, pushing the game towards a positional contest rather than a tactical one. I’ve been replacing the book openings bit by bit, and I’ve finally gotten to the end of that process. For now. (Though the short book reply to Scandinavian survived.)

My #1 model gm is Michael Adams. He’s a highly positional player who peaked at World #4. I’m now using a cross-section of his opening choices, though it hasn’t been a conscious decision as I’ve gone along replacing parts. In particular: As White it’s the French Tarrasch and 3.Nd2 in the Caro-Kann. I’m also currently adding for White the Rossolimo and Moscow anti-Sicilians. (I was using the Alapin as my anti-Sicilian but I didn’t love some of the directions it would go.) As Black vs d4 it’s the Nimzo-Indian, the Bogo-Indian, and the relatively new to me Queens-Indian. One advantage of all that overlap is that I can take his games using those openings as models for middle-game ideas. It’s sort of one-stop shopping.
As for “other stuff”: My main e4 opening is the Slow Italian, and I’m getting very comfortable with it. As Black vs e4 it’s the Caro-Kann, which is also mostly comfortable. As I’ve been adding new openings I’ve been cycling them through Chessbook a few weeks at a time, and I’ve been creating Lichess studies based around my openings as played by my model gms.
I’m sure that where I am now with openings now is only the tip of the iceberg, but I feel like I’m getting close to what I can use as a club-player-level lifetime repertoire. I know that I still have a long way to go to really learn the openings to where I’m happy with them, but that’s part of the fun.