If you're having issues using Pandora on iOS, try the following steps:

1. Reboot the device by shutting it down entirely, then turn it back on and try Pandora again.

 

2. Uninstall, then reinstall the app:  Hold down the Pandora icon on the desktop until all the icons start shaking.  Then tap the tiny "x" that appears in the upper left of the Pandora icon, and confirm that you want to delete the app.  Then re-install Pandora via the App Store on the device.