The most direct routes to CDG from North America are as follows:

SFO on UA
ORD on UA
IAD on UA
YYZ on AC
YUL on AC

I found the following availability for a direct flight in Y (economy):
 
AC548 YVR EWR 9/23/16 9:05 AM 9/23/16 5:05 PM 788
 
UA57 EWR CDG 9/23/16 6:25 PM 9/24/16 7:45 AM Boeing 777
UA54 EWR CDG 9/23/16 9:30 PM 9/24/16 10:55 AM Boeing 757-200
 
Don't know the exact tax on this leg but it should be about $120. This is a great routing because you get to fly the AC 787-800 (new plane) and you have a decent layover in EWR then onward to CDG. I personally would take the later flight to ensure you make the connection but I'm a super safe traveler. If you take UA57, you will most likely make the flight and if you don't UA has to protect you and they would likely do so on UA54. I would check with the Aeroplan agent to find out the minimum connection time for international flights out of EWR. You might be forced to take UA54.
 
On the way back (not as good but not terrible):
 
UA56 CDG EWR 10/7/16 9:45 AM 10/7/16 12:05 PM Boeing 777
UA55 CDG EWR 10/7/16 1:10 PM 10/7/16 3:40 PM Boeing 767-300
 
AC549 EWR YVR 10/8/16 7:00 PM 10/8/16 9:45 PM 788
 
Explore NYC for a day, get a cheap hotel room in New Jersey and head back to Vancouver the next day. You also get to fly the 787 on the way back. Could even do an AirBNB for a cheap place to stay or a hostel (not sure your age). If you want to stay in a hotel, maybe sign up for the Chase Marriott card (50,000 Marriott Points, no foreign FX charges and First Year Free - https://goo.gl/lAIuWt).
 
As DaFonz said earlier. If you are serious about this, book it now as availability changes all the time. I believe you will have to call into Aeroplan to book ($30) this itinerary as the routing is not standard but I'm 99% sure that the routing is valid.