You should be able to charge the iPod using the iPad charger (if that is what you meant), though if it's an older iPod be sure to use it's charging cord. Some of the earlier classic models used different pins to charge. If it is so old it uses a firewire port, then use the iPod's charger, not the iPads. At any rate, you can try it at home. I shouldn't hurt anything.
You might be able to trick the iPad into being a speaker with a combination of cords to convert the iPod's output to a mono-micorphone input and some recording style app. I don't recommend it. You can get a cheap portable speaker that will sound better for less money. Not to say it will sound very good, but neither does the iPad's speaker.