My flight is leaving on a Sunday morning at 7:40. I am staying in the Canal St. Martin area which I believe is not too far from Gare du Nord. I could get the first RER out, but would that leave me enough time at the airport? I am traveling through Paris alone and am a woman. So another question, is it safe to ride by myself at that time on the RER? If not, do the airport shuttles operate that early? Any info would be appreciated. Thanks in advance for your help!
On weekends the first RER B train leaves Gare du Nord at 04:56 and arrives at CDG 1 at 05:28 and at CDG 2 TGV at 05:30. Since you won't have many business travelers on a Sunday morning, I think you'll get through the check-in lines rather quickly. However, I recommend you find out from your airline what its check-in deadline is. If you use the same common sense precautions you would use at any train station at any time of the day, I don't think safety will be an issue.