Chrysler Town and Country 2009 31000 miles and it started having issues starting. We got a new battery and it seem to be OK for 2 dys then started having issues such that it only starts if you turn off AC and radio. It will click but that is otherwise. The dealer says alternator and starter OK. Why do I have to shut the AC and radio off to get it to turn over.

That does sound like a weak or faulty battery. Even though new, the battery may have a bad cell.
I like to say that new is an acronym for "never ever worked"
I would have the battery and the vehicle's electrical system tested by another shop. Something may have been missed, but you probably need to warranty that battery with the original supplier.