Is there a train from Toulouse or from Paris itself which goes directly to Charles de Gaulle airport (not the RER, but a regular train)?
Thank you. At this point, I'm not sure if we'll need train service from Toulouse or from Paris itself.
The only train from Paris to CDG is the RER. From Toulouse, you could take a TGV to CDG but if by direct you mean without having to change trains at a station, I believe the answer is no. You can check to see if that is the case by making a dummy reservation for your travel date at sncf.com/en.
One transfer is the minimum, whether it's in Paris or in Lyon or Montpellier. In those other cities, you'd make the connection within one station. In Paris, if you come into Gare Montparnasse, you can take Le Bus Direct to the airport. This is a 7-hour train ride, so I assume you'll sleep at an airport hotel before flying out the next day.
The DB link at How to Look Up Train Schedules and Routes Online can be an easier way to view schedules (not to buy French tickets) and also reflects RER connections (but not the bus option).
From to Toulouse to CDG the most direct and easiest is by plane. There are several flights a day.