All pages for the site live inside the Content folder.
A page is just a text file. The name of the file is used to generate the url, the content is automatically rendered into HTML.
Keep page names simple. Letters, numbers, spaces, hyphens and underscores are all perfectly ok. Spaces will be automatically converted into plus symbols for URLs. The file extension (e.g. .txt) doesn't matter, and will be automatically hidden in URLs and links.
The default page for any directory should be named "index". If there is no file called "index" then the first file alphabtically will be used instead.
To control the ordering of pages in navigation, you can prefix a filename with a number, e.g. 1.my-page.txt. Numerical prefixes will be hidden from URLs and links.
To hide a page from navigation links, prefix it with an underscore, e.g. _my-page.txt. You can still navigate to this page without the underscore.