This is always my recommended route for someone who’s trying to retain early/common grammar, and move forward with learning more grammar.
When reading, you’re seeing the same (common) grammar over and over, in various situations, and with various words. This causes your brain’s pattern recognition go to work, and you slowly shift from simply knowing about the grammar to actually internalizing it. And this makes it a lot harder to forget.
Having started myself with my first manga read being a text-packed 4koma with no furigana (before I started using WaniKani), and no book club, spreading the volume over maybe about 180 days, it’s amazing what one can do when it’s a series they really want to read!
But that said, I agree on starting by joining the Absolute Beginner Book Club. Even if it’s a manga you’re not 100% interested in, so long as you enjoy it, you can keep moving forward, and you gain a lot by asking questions and reading answers.
Our next manga will be the one to start with to jump into reading, because chapters are about 8 pages long, typically with low amounts of text, and (in the first volume) chapters are fairly stand-alone. That means you don’t have to worry about missing out on too much if you don’t fully understand some things along the way.