Hey Troop!
Congrats on the trip. You will definitely have a great time in France. We were in Europe for 3 weeks last Nov/Dec and had a great time. Here are some recommendations.
1. Dress warmly. Temperature may vary drastically from one region to another. We arrived in Venice in mid November and enjoyed perfect weather. It was snowing outside on the day we left (connection flight out of Munich).
2. Currency exchange. Airports have good conversion rates (relatively). Be careful with the currency exchange booths in different parts of Europe. The rates may look favorable, but they take a big commission fee. We met someone that needed cash and had to use a local currency exchange place. $100 US got her 55 euros. I'm not kidding.
3. Theft. Be VERY careful with pick pockets. We were warned by friends and acquiantances to not carry flashy jewelry and try to not look too like a tourist. However, it was pretty bad as we saw people getting their wallets, CC, and stolen. This happened in 80% of the cities that we went to, but it was the worst in Rome, Athens, and Barcelona. Hopefully Paris, London, and Amsterdam will be a bit better. Never hurts to be extra careful.
4. Train and metro schedule. Read the fine prints carefully. The "Gare" schedule is different for different days of the week and going to different directions. Some trains will be available every 15 min going one direction, but in the afternoon, have a 2 hour gap. We found that out the hard way.
Anyhow, we went to 7 countries and 18 cities or so during our trip. PM me if you want to see photos or get more info.