can't see bottom 3 columns

i now see the three columns.
so each spot is just listing posts in descending order, ok

i would like the categories and post titles below them in the gray three columns. (see png above.

here’s a webpage that has a site that has an example of what i’m looking for. it also mentions code. but i’m not sure if it’ll work on the theme i’ve got, Expound.

https://stackoverflow.com/questions/18111361/list-wordpress-post-titles-from-one-category-in-multiple-columns-in-alphabetical

instead of posts titles being in alphabetical, i’d like descending date.