Yes you should sleep as much as possible on the flight. If you arrive in CDG early in the morning then it is a good idea to get a hotel room and try to sleep till midday. Don't sleep too long. Then go out, enjoy your day and try to get to bed at your normal sleeping time. That way you should avoid jetlag, the next day you should be on normal time. If you don't arrive very early, you have to fight through the day to stay awake as long as possible. It is very tempting to try to put your head down and get a nap late afternoon or early evening. My experience is that just messes you up and you will still suffer jetlag the next day. Others may disagree, but that is my experience. As noted above, sunrise will be earlier than you are used to.