How to adjust for 1 column & no side bar

Basically my goal is for a set up very much like the sample shown. Just images and the titles below. I’ve downloaded Photography Business hoping to do that but in trying to “customize” I find no way to eliminate additional columns or sidebars. I can change their colors but not eliminate them. I’ve also not found anyway to add titles below each image as shown in the sample.

A little assistance would be great!