To create new pages navigate to Website > New page, choose the type of page and give it a name, the slug will be created automatically and is part of the url of each page.
You will find fields for: Name, Headline, Slug and Tags (separated with commas) in every page, also the option to upload Featured content slider images, Sharing or Thumbnail images.
The Sharing or Thumbnail images can be uploaded under Settings > Social media in every page, subpage, post or event. In some cases this image will appear as the thumbnail for example in Blog or Calendar pages; the Blog Post or Event pages need thumbnail images to show in the Blog and Calendar respectively and in the sections showing Latest News or Events.
To create subpages, navigate to the Subpages tab, then New subpage.