The navigation status bar and the items in the View > Pages menu are available only if the Multipage document checkbox is set in the Multipage Settings dialog.
The status bar contains information about the current page number in a text field and the number of all pages on a label.
It also contains a collection of buttons to aid quick navigation in the document.
All the navigation possibilities: go to first, previous, next, last, specific pages are available from the View > Pages menu as well.
Also, some automatic page zooming functions are available in this menu, these are as follows:
View > Pages > Fit page height: Adjusts the height of the current page to the height of the canvas.
View > Pages > Fit page width: Adjusts the width of the current page to the width of the canvas.
View > Pages > Fit page: Adjusts the height and/or the width of the current page to see the whole page, and places it centralized within the canvas.