my itunes store is not working

Hello there, shellymsu.

The following Knowledge Base article provides some great steps for troubleshooting your issue:

iOS: Understanding multitasking

http://support.apple.com/kb/HT4211

Particularly:

Additional Information

If an app doesn't respond to your input, or doesn't perform as expected, do the following, testing after each step:

1. Check for app updates.
2. Force the app to close.
3. Restart your device.
4. Update your iOS device.

Learn more about troubleshooting apps.

Thanks for reaching out to Apple Support Communities.

Cheers,

Pedro.