Use File->Page Setup to bring up the dialog box.
If you have multiple printers, use Printer to choose the right one. This can affect other options offered.
Choose paper size.
Choose paper source, i.e. sheet in the paper tray, or roll.
Choose orientation (for sheet feed).
Portrait = long sides of paper are vertical.
Landscape = long sides of paper are horizontal.
Set margins if necessary.
Page setup must be repeated if any of the settings need to change.
