You should hand the iPod into your local police station.
If you have performed a "full factory reset" (known as a Restore) using iTunes, then you have removed all information from the iPod (with the obvious exception of its serial number). Even if you have simply reset the iPod, there may be no information on it about the owner or his/her whereabouts. However, if there is an email address on it, you might be able to contact the owner if they can access their email on another device. Perhaps the Contacts section has a family member or an ICE entry (ICE is In case Of Emergency, which would usually be a relative).
I recommend that you use caution if you contact anyone whose entry you find on the iPod. You don't know them. In most parts of the world, your local police station is a wiser move.
Apple have no process that would assist you in finding the owner.