Like the man in Pulp Fiction says, we've got all the same stuff here as you do in the US but its the little differences that make it unique. Also like Pulp Fiction I have seen the french drown their french fries in mayonaise.
The french love their bread. You can find regular loaves of break in the grocery store, but no one buys them except for children. If you want a sandwich you buy a baguette. If you look hard enough you can buy a baguette in the states, but you have to look. For the uneducated in breads, a baguette is a very long thin piece of french bread. It looks like the bread you get a Subway sandwich on, but usually longer. The funny thing about it is that it pretty much dries out in one day, so you have to buy them every day. Luckily you can find a boulangerie on just about every corner. Those are little bread shops that sell all types of baguettes and lots of breaded pastries and things like doughnuts. Its such an odd thing for an American to see. Literally there are these little bread shops everywhere. But that's the French, they want their baguette and maybe a little dessert all the time. Then there are the patisseries which are just dessert shops. They have some of the same things as the boulangerie but their desserts are much more intricate.
To complete my subject the french are mad about cheese as well. In a typical American grocery store you will find a small section of cheese. Usually about 4 different types in bricks, sliced and shredded. Here the cheese takes us an entire aisle in most places. They have all kinds of cheeses I have never heard of but am bound to try.
Some other little differences...In the city you don't speak to anyone on the street or acknowledge them in any way. In the states I would often make eye contact with someone walking down the road and say hello or nod my head or smile. Here that doesn't happen. Yet when you go to a store you have to start the conversation with "bonjour" or "bonsoir" (good day, good night) and when you leave you say "avoir" or "bonjournee" or "bonsoiree" (basically goodbye) It is considered highly rude if you do not.
Cashiers at grocery stores or big wal-mart kind of stores all have comfortable chairs. No standing all day on your feet like in the states.
Their aren't bills smaller than a 5. Anything smaller is a coin. So you build a lot of change quickly and its not just like nickels and dimes it could be a 2 Euro or 1 Euro piece.
Alright I tire for now...