I stayed at the Concorde many times at the last company. It is a great hotel, but most of the rooms are smoking. There is a shopping mall/arcade in the basement, and there is a money exchange plus ATM. And, there is a Metro station as well, "Port Malliot". You can walk from the Concorde towards the Arch de Triumph, down the Champs Elysees, towards the Trocadero, then cross the river to the Eiffel Tower. Paris is a very walkable city, and Metro works great. Stay away from areas like La Defense, and other slums. Try the Latin Quarter, across the river, where MANY great restaurants reside, many cheap as well. I can taste the delicious food and fantastic desserts now.

Enjoy.