The Scope theme has two widget area’s that can perfectly be used for placing a banner, After Header and the Before Footer Widget area.
To add a banner you first have to upload the banner to the media library. Next you have to copy the URL of the banner.
Navigate to Appearance > Widgets. Place a text widget inside the After Header or/and the Before Footer widget area. Next step is to add some HTML.
Paste the URL of your banner in the code and change the link of the banner. Is this example the banner links to the WPStudio website. When your done save the widget.