I have been to Paris numerous times, one time right after the Gulf War. I have never had any problems. That said some basic things help.
Learn a few french phrases. Especially things like hello, thank you etc.
Don't expect it to be like home. People in general don't like being told that everything is better where you came from. (Yep, I have seen the Ugly American yelling about the coffee, pretty much a guarantee that they won't like you.)
Don't take the waiters personally. Yes, they can appear to be rude. The French don't get into the waiter introducing himself and making friends. Notice they are rude to fellow frenchmen also!
I love Paris and I want to go with you!