Breaking Up A Div

Weird question. This is the site I’m playing around with.

https://www.redcowboydesigns.com/otm/

It’s based off of Twilight 1.1. My question is . . . there is a main div for the body. Which is all white. I want to be able to break that div up or create another div that will allow me to have the space for the content (text) white. And then for the left and right filler space to be an image. Currently there is only one space and that is for the body which is all white. How would I go about breaking that up to include a separate div on the side so that i can change the color or add in a tiled image?

I’m not talking about the sidebars. But the actually space on the left or right.

Any help would be greatly appreciated!!!

Thanks!