Getting a 17 yr old, traveling alone, from Charles de Gaulle airport to a train to Lille

There are many direct trains from CDG to Lille. What terminal is this 17 year old landing? If Terminal 2, it is just a matter of following the signs to the airport train station.

Direct trains to Lille depart about hourly from Charles de Gaulle TGV station Terminal 2. Tickets can be relatively expensive to buy on the spot (about $70), but that might be preferable to the added stress of trying to reserve and meet a particular train. (If doing so, allow at least 3 hours from flight arrival time but know that the advance-discount ticket is worthless if he misses the train. There are a few cheaper departures branded as "Ouigo," but those tickets must be purchased online and earlier check-in is required in the station.)

I'm not aware that dedicated help is available to really guide him through, but there are staff available to answer questions. He should plan ahead using info from EasyCDG, such as:

http://easycdg.com/airport-guide/terminal-guide/terminal-2-paris-cdg-airport-charlesdegaulle/

http://easycdg.com/passenger-information/arrivals-cdg-airport/

The average young man or woman should easily spot the signs all around CdG (admittedly a fairly complicated layout) to find the Terminal 2 rail stations. The proper one is for the oui.SNCF high-speed trains, not the suburban RER station in the same area.

The young person can do the advance internet research now, as practice for independence.
Aside from the links suggested, www.seat61.com is the best guide for train travel anywhere and may come in handy for further travel.

The fast train requires a seat reservation, included in the price. Trains go to Lille in under an hour. And they depart at least hourly in the middle of the day. Flexible tickets allow a change in departure and seat reservation, allowing for airplane delays, at substantially higher cost and a visit with a reservations clerk. Right now the basic prices for a couple of months ahead are very reasonable, especially for those under 26. A ticket bought at the station on arrival will cost much more.

https://en.oui.sncf/en/results/?wishId=5cb74b4b67587b0c60346188&interstitial#!/

If the 17 year old is responsible enough to travel alone to CDG, s/he will be able to get to the train station to take the train to Lille. Get some detailed instructions by looking at the map of the airport so s/he knows what to do.

"Flexible tickets allow a change in departure and seat reservation, allowing for airplane delays, at substantially higher cost and a visit with a reservations clerk."

To clarify, these are regular, full-fare tickets, for the same price that you'd pay at at the station. They only allow changes and refunds until 2 hours after the original departure time. If you had a significant flight delay, they could still be worthless. I'd rather pay that price in the station than in advance. It's possible for a reserved TGV train to full up, but given the number of departures on this route I'd think that unlikely.

You tube can really be a help in a situation like this. There are probably several videos online showing CDG and how to walk to the train station or what the train station looks like. They will also show how to buy tickets.

My guess is that the 17 year old can find videos on you tube with no difficulties that will decrease any difficulties in getting to the train station.

How much do you want to pay? There are meet and greet services at CDG. Air France offers something but I do not know a lot about it other than it exists. The service I know about is La Conciergerie. It might be more than you need but they meet you at the door of the airplane, take you through border control, collect your luggage and take you to the doorway of your connecting flight for 200€. I would check with them to see if they offer that service but endIng with getting the person to the train station. My husband’s employer used it for a business trip to India with a short connection time at CDG. La Conciegerie offers more expensive options but their base plan sounds more like what you are seeking. I’d have paid the 200€ for my daughter when she was 17 because she would have needed it. Other 17-year-olds might not.

Re "trust worthy services" - no, a 17-year-old in France would be expected to do this trip on their own.
As the others said, there are direct trains from Charles de Gaulle airport to Lille, there is no need to go into Paris; and comng from an intercontinental flight it is best not to buy in advance, buy a ticket for the next train at the station.

This 17-year-old is presumably flying on their own, and getting from Lille station to their final destination on their own. Buying a ticket and getting on the correct train should not be impossible. They can always ask.

Thank you for all of your comments and suggestions!
I have a plan to get them ready and feel much better about sending them.

They can always ask for information at the CDG train station of they need help. You'll just have to tell them what to expect. I took the trip from CDG to Lille 1 Xmas ago and it was pretty fool proof.