Getting more space for the content

Can you show us the webpage?

to adjust the column widths in static pages, try to add some CSS like this, for example via the ‘Additional CSS’ section in ‘appearance’:

@media screen and (min-width: 48em) {
   body.page-two-column:not(.archive) #primary .entry-content
    {
      width: 73%; /*was: 58%*/
    }
   body.page-two-column:not(.archive) #primary .entry-header
    {
      width: 21%; /*was: 36%*/
    }
}