I would add that it is sad to be in Paris and seeing some tourists standing on a corner and trying to decide what to do next. You should be very familiar with the city, distant's between sites and, restaurants, etc etc. best means of transportation to travel between each etc. A good source are the books in Barnes and Noble's, the internet etc. A good start is a city map of Paris and circle all the sites you want to visit and the distance between each. That will let you know if you can walk the distance vs knowing best means of transportation. Almost all speak English or it is easy to communicate. As regarding security. Treat Paris like any other city you would visit, (e.g.NY, LA, Miami, etc.) Although European cities are more prone to non violent crime like pick pockets than in US and have less violent crimes. Just some follow ups.
