Q: ipod trouble

These are the minimum requirements for a new iPod nano.

• Mac: USB 2 or 3 port, OS X v10.7.5 or later, and iTunes 12.2 or later5
• PC: USB 2 port, Windows 7 or later, and iTunes 12.2 or later5
• Internet access required; broadband recommended; fees may apply

Above information from here >  iPod nano (7th generation) - Technical Specifications

If your Mac is running v10.6.8 as your profile suggests, then you need to upgrade to at the very least v10.7.5 (Lion).

Lion is available for purchase from the Apple online store > http://www.apple.com/shop/product/D6106Z/A/os-x-lion

OR, you can see if your Mac can upgrade directly to v10.11 El Capitan for free >  Upgrade to OS X El Capitan - Apple Support