It is very easy to create multi-level drop down menus for your website. On the Pages > Add Page / Edit Page sections you may choose where your webpage is located in the navigation menu by choosing its Parent Page - or make it a Top Level page (just choose "Top Level" in the Parent Page menu) for it to be the top tab on your menu. You can create unlimited levels for your drop down menus with this method. The page Label property is the title that will be used for the Menu Tab/Link Label, as noted on the Add Page / Edit Page.
You can also move the navigational location of many pages at once on the Pages > List Pages page. Click on the checkbox to checkmark/select the pages you want to move, select the Parent Page - or select "Top Level" in the menu to move page at the top - and then click on the Move link or image icon to move.
If you do want the page to appear in the Menu, make sure you choose the Link Position "Menu", on the Add Page / Edit Page.
There are other uses to a page having a Parent Page, and organizing the page levels, but having the Link Position "Other", instead of "Menu" - for example having a dynamic Horizontal or Vertical Scroll for Same Level Links or Sub Level Links (see Page Horizontal & Vertical Scrollers)