That sounds to me like a 7th generation nano, that looks like this:

which has the newer lightning connector (bottom of picture, right hand side) and a standard USB plug on the other end. It looks like this:
If you have lost this cable, you can buy a replacement from Apple, here: Lightning to USB Cable (1 m) - Apple
(that's the US store. If you're in another country, just look in your country's Apple store), it's the Lightning to USB cable. The other end is a standard USB plug, that you can plug into your desktop's USB port, laptop's USB port (you will probably need to have the laptop's power supply plugged in), or any USB power supply that can provide at lest 500mA. Look on the label of the power supply fr that figure. I have one USB supply that can only provide 250mA. It's not enough and it will not charge my iPod.
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The previous iPod nano to that one is the 6th generation and looks like this:

but I'm fairly certain it was not available in pink.
If I'm wrong, and you have one of the 6th gen nanos, it has the 30-pin dock connector cable rather than the Lightning Connector. I'm not sure that Apple still sell that one, so look online for Apple's 30 pin dock connector to USB cable.