Paris is expensive in all aspects, and many Americans who are not into the high-class foods may find it difficult to find enjoyable food, that you would be willing to pay for, ie. 12 euro hamburgers without the bun!
Quick Tips:
Paris McDonald's has a great deal on breakfast, 5 euros gets you a ton of food, muffin, juice, yogurt, and a few other things.
The Louvre is seriously discounted, half price at least in late afternoon, but it is huge so if you plan to see a lot of stuff this is not a good option. Try to do the Eiffel Tower early in the morning, before the crowds hit, Sunday is best.
Best Way To Get Around:
METRO! This is just about the only way to get around to all of Paris without spending a fortune, you can purchase cards that will hold certain amounts of money, or by the day, this is best so you are not always buying new passes every time. Be prepared when you are getting on the Metro or you will get run over, and it is also a good idea to keep you wallet in hand at all times! My dad just a few weeks ago nabbed a guy trying to steal his, he said there were at least two guys in on it, so keep you eyes open.