There are 3 different ways to add in navigation menus - drop downs, external links, and custom page.
Click on Navigation Menu
Name your Category
Save and make sure it is active on your website
Click on Edit Navigation and you'll now see your category in the drop down. Select a page and you will be able to include it as a drop down in your category.
From the main menu, click Navigation Menu
Add Menu Item Hyperlink
Name your link and follow to step 2. Paste your link with the http://www.
Back to navigation menu --> Edit Navigation Menu --> Make sure the link you named is activated and save it.
From the main menu, click Website Content
Add Custom Page panel
Choose a display name, page title can be the same as display name. Click Next Step
Fill out your custom page with content and save.
Return to main menu and click navigation menu --> Edit Navigation
Make sure your page you created is active and save.