Acces No, 1 will get you to Passport Control faster. Before you arrive, you should ask the FA for an Acces No. 1 coupon. If FA does not have it, then ask the United gate staff who meets the flight. Follow the Acces No 1 sign which will point you to a different area than the regular immigration line.
If your flight is on time, you should be fine. CDG is tricky so feel free to ask questions to airport staff.