Help assigning Book sub categories

Hi all, I just posted my first book online and the listing doesn’t seem to have any categories attached to it. I’ve tried to find tutorials that show how to change the sub category but so far all the ones I’ve found seem to indicate I need to change options I’m not seeing in my listing page.

Is there something that i’m missing? How do I update the sub categories to get my book to properly show in (for example) books> children’s > holiday instead of just #123,546 in Books? TIA!