Firstly, you have posted in the wrong area. This is the area for Mac OS X Server. You'll probably get more help if you go to the correct area.
But in the meantime, find the serial number for your macbook:
Then go to this website:
Enter the serial number for your laptop into the field at the top, and press enter.
Then scroll down and look for this field: "Maximum OS:". That will tell you the latest OS your computer is capable of.
I'm guessing that you can probably run Mac OS X 10.7, and that'll allow you to use itunes to sync your ipod nano.
If you're not able to follow the instructions that I've posted, then you should probably bring your macbook to your local apple retailer / apple store for assistance.