To change your Navigation Bar (Menu) you need to click "Menu" in the Admin Page.
You have a standard Default Menu. No need to delete this or add more! Click on "Default Menu" to begin editing your navigation.
When editing your menu you can change the name and add "Related Menu Items". Related Menu Items is where you build your navigation bar. You can have a Max of 6 Menu Items any more than that will cause format issues. You can have unlimited drop down items within those Menu Items though.
Click "Edit' on Related Menu Items. The system recognizes all menu items. Choose the six that will best represent your site.
Now hit "Submit" to save your changes. Your Navigation Bar/Menu is complete!