Welcome to the forums cokebear.

Here is a list of Taxis and Cabs in New Orleans. They might be able to help answer your questions about child safety seats. I would expect some of the cab companies carry child seats with them... but, you may want to find out which companies do ahead of time.

Where are you staying? Pretty much everything in the French Quarter is within walking distance of most major hotels. Bring a stroller (or buy one when you arrive) and you may not need a taxi...

Don't forget to visit the Zoo and the Aquarium...

And, if you like seafood... you MUST try Redfish on the Halfshell at Bourbon House Seafood (they also have quite a collection of Bourbon if you like whisky! )