You have to update via iTunes on computer
No, you do not need an internet connection to back up an iPhone using iTunes. The backup process occurs locally on your computer, where iTunes stores your device's data. However, you will need internet access to download iTunes or update it if it's not already installed on your computer.
There is no way to update your iPod from your iPod. You have to do it on iTunes on your computer.
To update an iPhone using iTunes on a computer, first connect your iPhone to the computer using a USB cable. Open iTunes (or Finder on macOS Catalina and later) and select your device when it appears. Click on "Summary" and then choose "Check for Update." If an update is available, click "Download and Update" to begin the process, and follow any on-screen instructions to complete the update.
On a Mac click on the Apple menu icon (top left corner) and select Software Update... from the menu. This will check what new versions of software are available for your computer. Software Update will then offer you the choice to install the available new versions of your software.
Plug it into your computer, open iTunes, click update on the main screen.
New iTunes software can be installed to update the previous version. Only the iTunes software is updated the iTunes library with your music/videos etc. is not affected by the update.
No. Your iTunes Store balance will remain on your account, but you should update the email address associated with your iTunes account to keep your info up-to-date.
Plug it into your computer and iTunes will open automatically. If you don't have iTunes download it from apple.com. When iTunes opens you will see under devices your iPhone name will be there. Click that and then press check for update. If there is an update available, download it.
Sync with computer running iTunes. Update.
You need to connect your touch to the computer, then open iTunes then select update. This will update your device.
plugging the ipod to your computer and open itunes, it should prompt you about the update