Q: ipod error message

As a test, shut down (power off) the computer and disconnect all USB devices.  You can leave standard USB keyboard/mouse connected, if used.  If your computer is a laptop, connect its power adapter so that its not running on battery power.  Do this to Reset (restart) the iPod

Learn how to reset your iPod - Apple Support

Start up computer, run iTunes, and connect iPod to a direct USB port on the computer.  Is there any difference?

Since you are having other iTunes-related problems, you may want to try uninstalling iTunes and related software components.  This Apple procedure document lists the iTunes components and the precise order to uninstall them

Remove and reinstall iTunes and related software components for Windows 7 and later - Apple Support

After completely removing iTunes, download and re-install the latest version

https://www.apple.com/itunes/