The Euro Dollar is the currency of France as well as the European Union. The Euro dollar has 100 cents just like the American dollar. The American dollar is not taken in France and you must exchange it for euros.
Physically exchanging American dollars for euros at an international bank can be done but will get you the best rate of exchange. The best and easiest way is a bank ATM card and of course Visa or Master Card. Just make sure they know you are going to France or they may lock your account when they see it has been used in France, thinking it was stolen.
The paper euro dollars increase in size as the denomination increases. The 20 euro bill is to wide to fit in a regular bi-fold wallet but will just fit in a tri-fold wallet. The 5 euro is the smallest paper bill and there are larger ones but as in the US, the 5, 10, and 20's are one most people use.
The coins are where the big difference comes in. There are 2euro and one euro coins, also 50 cent, 20 cent, 10 cent, 5 cent, 2 cent, and 1 cents coins.
My son still maintains an account with a local bank about a block from my home and I knew his ATM card would work. I deposited enough in his account so I would have 100 euros to start with. I took no cash and just used plastic to get money from ATMs and pay for our hotel rooms. I felt comfortable doing it this way because I knew if a problem arose with my cards that my wife could just put more money in his account. I didn't have any problems at all but it was nice to know I had a backup.
My exchange rate was about $1.38 US for $1 Euro.