How to Reduce Margins in WordPress

In the late 1990s I developed my first website of 350 pages using HTML Goodies. As rules changed I tried to keep up with them, but it was difficult with that many pages. Of course, CSS helps but now Google no longer lists my website, which is https://www.villageprints.com. I am planning to keep the Village Prints website at least until I can get my new site with WordPress, https://www.hometowndrawings.com, up and running. I also have thousands of prints throughout the USA with the Village Prints website printed on them. I would like to keep the Hometown Drawings site with the same look that I have on Village Prints site, but that probably is not possible. I am using Twenty-Ten CHILD THEME, and I am trying to develop a template page that includes 4 columns without the sidebar. I am developing a group of 12 pages to take the place of those found when you click on each state in the Village Prints site, https://www.villageprints.com/states.html. I have produced a 4-column page without the sidebar, but the page has as much negative area on each side of the columns as the columns take up. The link to that page is: https://www.hometowndrawings.com/drawings/alabama-towns/?preview_id=353&preview_nonce=e2f632fd69&preview=true. I need the columns to take up most of the width of the page. I will also need the template page without sidebar for more than 300 pages to take the place of pages similar to https://www.villageprints.com/lexington-tn.html. I would appreciate your help in setting the margins on the template pages.