First Burn ^^

Depending on the books you choose, and sometimes based on the editions, they will come with full furigana so you can even read them without knowing any kanji. Vocab and grammar are much much more important. But full furigana will mainly be in books aimed at (younger) children.
If you plan to read adults‘ books, though, level 24 won’t help you that much … We read a couple criminal stories with the book clubs, and I had a feeling that I knew most (but not all!) kanji around the mid-to-end 40‘s levels.
Having said that, if you want to read books, you can start as soon as you have some basic grammar under your belt. You can check out the Absolute Beginners Book Club // Now reading: Hunter × Hunter who just started a new book yesterday :blush: