Cassie,
Irfanview is the easiest to use. At the top toolbar choose Image/scroll
down to resize. 2nd box on left choose button switch to "set new size".
Choose inches in the button switch, choose 5x7...Also VERT IMPORTANT
use this screen to resize photos into smaller files when emailing. If
emailing to a website in order to have them printed, email only the
original or the largest file you have. Remember that if you save the
pix as a jpg and open and close it alot after editing it, you will lose
some sharpness.
Keep trying. There are no dumb questions
GG