iPod connected but not syncing

I have my I-don't-know-what-gen iPod Classic (160GB, bought in 2012) connected to my iMac via the USB port in my keyboard and it's showing up in Finder and in the Music app, but it doesn't seem to be syncing. It's been plugged in for about 3 hours now, (to be fair it also took some time to actually even show up in the thing), but it's just "Connected". I can;'t click sync or anything.

Is there anything I can do about this or could it possibly be because, um, my cable looks like this: