Whenever you want. 
Also, all of the book clubs, even the Absolute Beginner, are about being an absolute beginner at reading native material, not in the language itself, since even the simplest manga has grammar points that could be from N5 to N3. Or a lot of vocabulary that you don’t know yet, but that’s why the book clubs exist, so you can ask questions and look stuff up more easily since there are vocab sheets and people there. 
Btw, the next book club is in 2 days: チーズスイートホーム Home Thread (Absolute Beginner Book Club) - #137 by hinoshori
So you might want to take a look at the sample pages and see if it’s something that you would like to read, then join the book club and give it a go, or wait for the next one. 