To add a new page to your site, hover over the Pages tab in the CMAdmin bar at the top of the screen.
Give the page its appropriate name, and click the drop down next to 'Insert'. You can insert the page before or after a specific page or make it a child of a page.
Click the next drop down and select the page you want the new page to go before, after, or be a child of. Then click 'Add Page'.