How do I keep my ipod from repeating songs

The Repeat setting is probably set to Repeat One (repeat current song). If your iPod nano has a touch screen, this setting is on the Now Playing screen. Tap the screen. The button for Repeat looks like two arrows in a loop. If it's set for Repeat One, the symbol has a small "1" in it. Tap it to change the Repeat setting. Take a look at the user guide (page 19) for more info

https://manuals.info.apple.com/MANUALS/1000/MA1624/en_US/iPod_nano_2015_user_gui de.pdf

If your nano is 6th gen, you may need to swipe the Now Playing screen.

If your nano is an older model with a click-wheel, go to the iPod's onboard Settings screen. Find the setting for Repeat and set it to Repeat Off or Repeat All (repeat current list).