At the moment, I don’t see any columns or space on the right side of your website. If this is still an issue, could you share a screenshot, so I know where to look at.

From your description, I think it could be a sidebar. You can check for sidebar widgets under Appearance > Widgets. If you’d like to disable the sidebar fully, then go to Appearance > Customize > Pages > Enable Sidebar. Make sure you have this disabled.

If this doesn’t work, then the screenshot will be helpful.