Columns of text boxes?

one possibility:
https://www.transformationpowertools.com/wordpress/posts-in-columns-a-new-twist-on-an-old-problem

should actually be ‘in rows’ as this is the way the posts are arranged;

three per row is not enough to call it a ‘grid’ …

Thanks for the link, but where does this code go? I looked at the “Zebra” example too, but don’t know (as a beginner) where to put it. Again, is there a tutorial/book that would bring me up to speed on this sort of hacking?

where does this code go?

generally, into the loop, possibly in index.php; details depend on the theme you are using.

I personally wouldn’t know any books or tutorials to recommend

– maybe make a new topic under ‘miscellaneous’ to ask about these kind of things.