My program is printing on 2 sheets and I want it to print front and back.

If you do not have a printer that prints front and back at the same time, you will need to flip your paper over after printing each page. So for example, send it to print page 1, then flip the paper over and print page 2. If you do have a duplex or two-sided printer, there should be an option in your printer properties that indicates double sides or back to back printing.