Mona,

Put the printer setting back where it was.  If you don't
have a Page Setup ... command on your File menu then it
was deleted at one point.  

You can get to Page Setup from the View>Header and Footer
toolbar.  Display the toolbar and then click on the open
booklet icon.  Select the Paper Size tab and click
Orientation>Landscape.

To correct your File Menun issue,
View>Toolbars>Customize.  Use the Commands Tab, File
Category, scroll down the commands list until you find
Page Setup ... drag the icon and drop it on your File Menu.