Go to Websites > Pages > Add a New Page (or select an existing page)

When creating a new page, the "Template" field will have the "Subpage Default" template selected as the default. You can select the dropdown menu to change to the "Subpage Default" template, if needed.

The page will automatically display in the header image area (above the content area is no header image is used). The checkbox "Hide Page Title" removes the title from the page.  

The page description field is optional and can also be used to help with SEO.  

Displays the billboard/header area at the large screen height

This check box option will add a blue screen effect overlay to your header image, so the text overtop is more visible.

This will add an optional sub heading in the header area below the page title.  

This will add content over-top of your static header image or background video. This works the same as the page content field, so you can include text, buttons, etc. The text will display centered as the default.