i own a iPod touch 4th generation (v.6.1.6)

Apart from being unable to update or sync any new app, I can't even verify my apple ID to download podcasts or other iTunes features into this device.

i would love to use it for podcast listening — but the verification code, after i enter my apple id password start with two letters and i don't know where to get it (as my iMac give 6 nr figures)

HELP.