By default, your content will show on a full width page layout. However, you can have your content stand out with a boxed style effect where the main content area in the middle is centered with a background colour. Here is a screenshot showing a before and after; might be a bit hard to see that the content is wrapped in a white container with a bit of padding added:
Using this feature gives you the option to change the page background colour or adding a background image.
Go to Appearance >> Customize >> Theme Options >> Basic Options
Look for the “Add a Content Background” setting and check the box.
You can also change the background colour for the content wrapper by going to the “Colours” tab and change the colour setting for “Content Area Background“.
Click “Save & Publish“.