Editing The Site Structure
Once you have signed into your site, you will see a text link called "Edit" and when you hover over it, it says "Edit Site Structure".

This is where you add folders and pages, move them about, delete them or amend their names, add properties and set up password protection.

A = Access

P  = Properties

E  = Edit

M  = Move

X  = Delete

How to add drop down menus, new pages, links to external sites
If you choose ADD you will see that you can add a Folder, a Page or a Link.
If you choose folder you can make a folder and add pages to it so they appear as drop down items owned by this folder, or you can just add a page [either as a top level pages, or to an existing folder]. You can also create a link page - which might be a link to an external page or to an existing page of your own web site.

Simply click on ADD, name the page or folder and click save and then continue. You can then go to the sections page to see what you can do with your newly created page.