When you are working on a long document, you may want to see two facing pages on screen.
To switch from one page view to two facing pages view, click on the scaling drop-down menu in the bottom left corner of the document and choose Two Up option. In User's Manual it's called Page View control.
You will now have to facing pages displayed on screen.
To navigate through a long document you may find it helpful to have 'Show Page Thumbnails' option on. It is under View menu on the left in the document Toolbar or under the View menu at the top of the screen.
When you click on a page thumbnail in the side panel, you are taken straight to that page.