Was the iPod previous synced to another iTunes library/computer?
Have you successfully synced from this iTunes library/computer before?
If so have you done anything like update iTunes on the computer since it last successfully synced?
Do the songs play in iTunes?
Does any media now sync to the iPod?
Do you have the right boxes checked to sync?
iTunes: Syncing media content to iOS devices and iPod
Try syncing using the manual method
Managing content manually on iPhone, iPad, and iPod
Last, backup to iTunes and restore from backup
How to back up your devices using iCloud or iTunes
Restore your device from an iCloud or iTunes backup - Apple Support