We didn't yet know you can't see it all . . .
We were young and restless and wanted to see France, all of it. We quickly learned you can't do that on one trip. However, if you're planning a longer trip in France and want to see more than major cities, here are some good ideas. It also gives you an idea of how to time a longer more rural trip.
If you come from the USA as we did, you will land in CDG or Orly. Take the train into town to your hotel and stay as centrally as possible. We planned 3 days in Paris at the beginning and 2 days at the end of our trip. The first time, we'd never been to Europe so it was a real adventure. We were also young enough to be poor enough to have to camp which turned out to our advantage. You experience an entirely different country when you get into the campgrounds. Country folks are not city folks in any country . . . and country folks are very friendly and helpful. This was our first experience of France and we've absolutely loved it ever since.
So . . . start in Paris.