Hello @neiljacobson and thank you for reaching out to the GoDaddy community where users help users out to the best of our ability.
My suggestions would be to click 'customize' on the top bar from the screenshot you sent. Then should be like a sidebars section/widgets area, where you should be able to remove the sidebar area that you are talking about. Then click 'update' within the customize section.
Let us know if that helps you out!
Some themes offer a full page option in their settings -- but that is site-wide. You would see that in a "Theme Options" Tab in the Customize area. Since your screen shot does not show the full scroll, not sure if that is an option for you.
Or you can check under Page Attributes > Templates to see what options are available there on a page-by-page basis.