how do i get my apps to open up and work? cuz my apps on my ipod will open but they will turn off and go back to the home screen after a couple seconds

Hey, I got a 16GB ipod touch that's new and i installed some apps and none of them work except for a few. Cause like whenever i click on one of my apps it'll open but after a few seconds it will go back to the home screen. How can I fix that?

Sincerely,
Makenna Berry