Hi kristinh,
There can be two different reasons why you can't see your Navigation Bar:
1. You have removed your Navigation bar module from your website.
To fix this, go to Modules tab of your WPB panel, find Navigation module and drag and drop this module to any place of your website where you want to have a Navigation Bar.
2. You have configured your Navigation Bar module in such a way that it only shows subpages of a current page. If you don't have any subpages on your website, you won't see this Navigation Bar on published website for obvious reasons.
To fix this, you need to access this Navigation Bar module and reconfigure it. When you edit your website, this Navigation Bar module should be visible and looking inactive with the following text: "There are no subpages for the current menu item to show in the navigation block". Click it and select appropriate option (I recommend "All Levels") under Levels tab.
Also note that you can have multiple Navigation Bars on your website, each possessing its own independent page level settings.
Hope this helps - let me know if your problem wasn't solved.