I have made this trip twice from the Paris airport CDG. You catch the train at the lower level and the signs are easy to follow: I've attached a link:
You will love the Primitivo and will finish on the Frances. It's a great time to be there and on my list to return and finish my Camino Primitivo which was cut shot by The Covid pandemic. I was there in April of 2020 but have chosen October for my return. Buen Camino!