Making a train on time at CDG after landing

You will probably not make the 7AM train even if you are in the front of the plane and have no checked luggage unless the flight arrives quite early. I mean just think about it: the airplane has to land and get to a gate and offload the passengers and then they have to make it to passport control. Then you have to orient yourself (it does not seem like you have been to CDG before) and then make your way to the train station. The usual advice is book a train leaving CDG 3 hours after your flight's ETA. When you purchase your train ticket, you may be able to choose tickets with flexibility but note that flexibility costs more than a lack of flexibility and I do not think that there are any that can be changed after departure time.

Seems unlikely but if you book a ticket with flexibility that you can change at the last minute; you could try it if you like that kind of risk.

Realistically go for the 9am train.
Only the higher priced flexible refundable tickets are exchangeable refundable if you miss.

I could take another train around 9, but I'm worried about my deadline in Marseille.

What time do you have to be in Marseille?

Unless you are coming from a Schengen area point, making a train 50 minutes after arrival is not realistic.

Here is a link to instructions form the terminal to the train station (about 10 minutes): https://easycdg.com/travelling-terminal-2-tgv-rer-station-cdg-airport/.

Thanks for the advice everyone. I booked the 8:29 train and paid the extra 6 euros for the "missed the train" insurance.

Even the 8:29 is a total crap shoot. I mean you might make it, but how can you know when you will even actually land, much less get off the plane and get through passport control.

The scheduled landing time is when wheels touch down.

This is no more true than scheduled departure time is the wheels up or '"off"' time. Scheduled arrival times are gate arrival times, and they have always been so.

Still, the OP will not make a 07h00 train departure with a 06h10 scheduled aircraft arrival time. 50 minutes is not sufficient time to deplane, make it through passport control, pickup luggage, walk through customs, and then make it to the TGV departure station.

Oh my. No absolutely not. You will not even be through immigration at 7 o’clock.

You read the passport control is fast? Where did you read that? because it’s not

But even if it is fast, you probably have to walk about 20 minutes before you even get to it and then you’ll walk about 20 minutes to the train.

People, the OP has already told us he reserved a later train. The 7 AM idea has been discarded.