The box above appears, click on yes to apply.
You can set up your pages to suit, anytime when working on your document. Click on the File menu/Page Setup
From here you can set your margins and layout. Set the orientation of your pages to be portrait or landscape.
Set your pages, click on the box that says Pages, Multiple Pages, and set your pages to 2 pages per sheet if you writing a book for instance.
Click on Layout Tab and you can change the alignment layout of your
pages, to centre, top or bottom.