You might consider downloading the DuoLingo app if you have a smartphone. It could probably help. There's an app for the parks, too, that's pretty handy. The bigger shows (think Mickey and the Magician, stuff on the castle stage, etc.) are usually bilingual. Smaller shows tend to have scheduled times for either English or French versions, so you shouldn't worry about the attractions themselves. Cast Members are usually multilingual, (at least English and French, and most that I've encountered tend to speak at least one other language as well) but it's a good rule of thumb to learn some basic phrases in the local language of a country you'll be visiting regardless of how bilingual they may be. It's just more respectful.
Excusez-moi should be used before addressing someone with a question, but 'pardon' is used if you bump into someone, generally. France isn't like Spain or Italy, where the formal form of address is hardly used. If you're going to try for full phrases, make sure that the 'you' form is 'vous,' not 'tu' when you're dealing with strangers. Most younger people don't care, but some do. Better to play it safe and use the most respectful terms.
If you're going to go into the city itself, you might want a bit more French than you will if you stay on Disney property. The respect you receive in Paris will be greater if you show the respect of not assuming people speak English in a country where the native language is French.
Oh, and the tipping thing? Frankly, after fifteen years here, especially if it's a place I'd like to return to, I always tip. The service is generally better when you do. It's a good rule of thumb if you're getting a drink at a bar. (Even if it's just at Planet Hollywood.) Tip well on the first round of drinks, at least, and you're more likely to be remembered and served quickly if the bar is crowded later on. Servers are paid a living wage here, but tips are still appreciated. They don't make a lot of money. Also, it's commonly assumed that Americans are good about tipping.
