Erase iPod touch
When you delete data, it’s no longer accessible through the iPod touch interface, but it isn’t erased from iPod touch storage. To remove all of your content and settings from storage, erase iPod touch. For example, erase iPod touch before you sell it or give it away. If you want to save your content and settings, back up iPod touch before erasing it.
You can erase iPod touch from Settings 
. If you’re unable to open Settings, you can use a computer to erase iPod touch.
Wipe all content and settings from iPod touch
Go to Settings
> General > Transfer or Reset iPod touch.If you’re erasing your iPod touch because you’re replacing it with a new iPod touch that you have on hand, you can use extra free storage in iCloud to move your apps and data to the new device. Tap Get Started, follow the onscreen instructions, then return to Settings > General > Transfer or Reset iPod touch.
Tap Erase All Content and Settings.
When iPod touch restarts with all content and settings erased, you have the option to set up iPod touch as new or restore it from a backup. See Turn on and set up iPod touch.
Note: If you’re asked to enter your passcode and you’ve forgotten it, see Reset the passcode. If you’re asked to enter your Apple ID password and you’ve forgotten it, see the Recover your Apple ID website.
Use a computer to wipe all content and settings from iPod touch
You can use a Mac or Windows PC to erase all data and settings from your iPod touch, restore iPod touch to factory settings, and install the latest version of iOS. For example, if you can’t open Settings on iPod touch, you can use this approach to restore iPod touch to factory settings.
Before iPod touch is erased, you have the option to back it up. If you make a backup, you can use the backup to restore your data and settings on your iPod touch or on a new device. See Restore iPod touch from a computer backup.
Do one of the following:
On a Mac: In the Finder sidebar, select your iPod touch, click General at the top of the window, then click Restore iPod touch.
To use the Finder to restore iPod touch to factory settings, macOS 10.15 or later is required. With earlier versions of macOS, use iTunes to restore iPod touch.
On a Windows PC: Install or update to the latest version of iTunes on your PC (see the Apple Support article Update to the latest version of iTunes). Open iTunes, click the iPod touch button near the top left of the iTunes window, click Summary, then click Restore iPod touch.
Follow the onscreen instructions.
See the Apple Support article If you can’t update or restore your iPhone.