Typically speaking, you should make very few changes to the menu navigation.
Your menu navigation needs to remain user-friendly and as streamlined as possible, when it's changed frequently it can become unhelpful or confusing to your users. Plus, there may be horizontal spatial limitations on how many menu options are optimal on the top of your website. Attempts to edit it without careful work can cause issues and broken links. When in doubt, contact us.
All that being said, sometimes you'll want to make some minor changes. To access the Menu navigation and understand its structure, go to Menus > Main Menu or click Menus from the Control Panel. From here, you can add or delete options, but setting up menu items requires having already created the content. For full instructions on how to add Items to your menu see the sections below.
If you need help making adjustments (i.e. adding an item or deactivating an item), you can contact Third Sun Support at firstname.lastname@example.org with your request.