I am arriving at CDG at 5.15pm terminal 1and was wanting to connect with the TGV to Avignon at 7.05pm.

Will I have time to connect and how do you get to the train terminal?

I was planning on not pre booking in case I don't make the connection.

From where are you arriving? That can make a lot of difference in the time it takes to get out of the terminal.

Allow up to one hour to clear immigration/passport control.

Take the free 24/7 CDGVAL driverless shuttle train from Terminal 1 to Terminal 2. Trains run every four minutes and the ride takes eight minutes.

To avoid waiting in line to buy a ticket at the TGV station, book a full fare refundable e-ticket online and print it yourself. Book in French at voyages-sncf.com. Book in English at tgv-europe.com and select Great Britain as your ticket retrieval country to avoid being bumped to the Rail Europe site. You still will be able to print your own ticket.

There are often long long lines at TGV ticket window at CDG when I have been there - do as TimS advises - there are automatic ticketing machines but I believe they do not accept American credit cards, which you can use at the counter however.

the connection will be tight and with your ticket comes a seat reservation and if you miss the first train then you will have to wait in line to re-book your seat reservation for the train four hours later - or you could re-book onto a train leaving from Gare de Lyon in central Paris where trains leave about hourly or so.

Buy your tickets online NOW. Get a refundable ticket. As noted, take the shuttle from aérogare 1 to aérogare 2 and go to the SNCF station between Halls C and D. It would be best if you don't check luggage so you can get off the plane and head right over.