The hop on hop off bus in Paris or any European city is easy to use even for someone who is not familiar with the city. It will take you to all the major sites. i Have been to France many times and have never gone to Disneyland Paris. We have not been that interested. Personally if going to Paris and France for the first time and maybe never coming back, I would spend most of my time in Paris and the surrounding area. It’s an easy train ride to Versailles and along the way you could stop in Chartres to see the beautiful cathedral and rose window,
The metro in Paris is incredibly easy to use. Any neighborhood is worth walking around. My fsvorite Spots are the Rodin museum and garden, the Tulleries, Montmatre, lunch in the ridiculously expensive but enthralling view at the Eiffel Tower restaurant, a nighttime cruise on the seine, the Pere lachaise cemetery with its incredible monuments and feral cats, sitting in cafes drinking wine and watching the parisians going by, But enjoy whatever you decide. It’s a wonderful country And city
And don’t believe all you hear about the French being rude. Yes they can be but usually only if you are the epitome of the ugly American. Just try to learn a few France words, laugh at yourself when you mess up, smile a lot and don’t talk louder as if that will help them understand you better. Also try to avoid tourist trap restaurants with the ever popular English menus with pictures. Go to small local restaurants, learn enough French words to order from a French menu, remember that Coke costs more than wine And don’t try to eat before 8 pm. When most of the local Restaurants open.
finally Be sure to get A Rick Steves guide to Paris.