What a fun time you will have!!
I agree with Carol, I would plan to do this on your own but if someone responds that is great!
Do go directly to the taxi rank outside the exit for Customs at CDG. Do NOT go with anyone who comes up and asks if you are going to Paris. There are blue footprints or medallions on the floor (can't quite remember, lol) as well as signs overhead saying Taxis.
Is your tour hotel Londres Eiffel? Asking because the flat rate for this Left Bank location is 62E. You can pay by CC. I usually hold up the CC to the driver before they load my bag and say "OK?". Have the name and full address typed out on something you can hand the driver including the arrondissement code which for Londres Eiffel would be 75007. I usually tape the address to a 3x5 card and keep it handy in case I need to take a taxi home from somewhere in Paris, lol!!
https://www.parisaeroport.fr/en/passengers/access/paris-charles-de-gaulle/taxi