In layout mode select everything, does ANYTHING extend past the bottom or right margin.
Very few printers can print from the top edge of the page to the bottom. Their printable area is usually less than 11". If even one pixel of your total layout exceeds the printable area for one page with your printer, you'll get that extra page.
Enter layout mode
Select your printer in print set up.
Select the correct page size and orientation.
Look for a horizontal line near the bottom of your layout marking the bottom limit of your printer's printable area. Resize things to fit inside that limit.
Margin setting inside Layout Setup can also reduce the printable area by setting top and bottom margins.