Hi,

The order of the pages in the navigation bar corresponds with the order in the "Pages" panel. That's also where you can actually change the order, simply by dragging & dropping the name of a page from its current position to a new position.

I'm a little confused about the second part of your question. Do you want to change the page name? This would just require a double-click on the page's name in the "Pages" panel. A new window comes up where you can type in the new name.