Recharge
If you see this screen or the screen says, "Charging.  Please wait…", keep iPod touch connected so it continues charging.

Use a high-power USB port such as the one on your computer, or use your iPod touch AC adapter (sold separately).
Don't use the USB port on your keyboard because it is a low-power port and iPod touch will not charge.

Try restarting iPod touch. To turn it off, press and hold the
Sleep/Wake button until the red slider appears. Slide your finger
across the slider to turn off iPod touch. To turn iPod touch on, press
and hold the Sleep/Wake button until the Apple logo appears.

Does iPod touch appear frozen or stuck? Try pressing and holding the
Home button for 6 seconds to close a frozen application. Then try
restarting iPod touch again.

Reset

To reset iPod touch, press and hold the Sleep/Wake button and the Home button at the same time until you see the Apple logo.

Remove Content

If iPod touch is
not working as expected, it may be due to some of the content synced to
it. Try selectively removing certain content that may be causing
unexpected behavior such as songs, contacts, calendars, photos, videos,
or podcasts. To remove content, connect iPod touch via USB and use
iTunes to change the sync settings. Click on iPod touch in the Source
list, and select each tab to change what content is synced and click
Apply.

Reset Settings

Tap Settings > General > Reset > Reset All Settings

Note: This will reset all settings.  No data or media will be deleted.

If that does not resolve your issue, try erasing all settings.

Tap Settings > General > Reset > Erase All Contents and Settings

Note: This will delete all media and data.  All settings will be reset as well.

Restore

Try restoring iPod touch using iTunes.

Connect iPod touch. When it appears in the Source list, click on Restore in the Summary tab.

Note: This will delete all media and data. All settings will be reset as well.