Shuttle from CDG to Paris

If you'll be staying in the same hotel where your France My Way tour starts, then the tour department will send you good directions for reaching that hotel from the airport. Similar info is in Rick's guidebooks. Shuttle vans are not particularly reliable and many require you to book a specific pick-up time. The RER train and selected private bus lines can each get you quite close to some lodgings, depending on location, such as the Les Cars/Air France bus #4 to Gare Montparnasse. Or, if your first stop is an apartment in the Latin Quarter, then the direct RER B line to either St-Michel Notre Dame or Luxembourg stops may come closest. Otherwise, a taxi for €55 will be simplest (this new, flat rate was announced recently and starts in March).

Air France buses. If your hotel is further than one of their stops, you can always get a cab the rest of the way.

http://en.lescarsairfrance.com/

RoisseyBus is an option, if you are staying anywhere in the vicinity of the Opera metro station... I boarded the metro there, but if you are truly averse to trains/metros, the RoisseyBus could get you most of the way for about 10 euros. Take a taxi from there and significantly reduce your fare.

To answer your question, I recently took a tour that started and ended in Paris. My hotel was able to book a shuttle that picked me up at the airport and took me back at the end of the tour. You might want to email your hotel to see if they have a recommendation or can set it up for you. I had no trouble and the shuttle was on time both picking me up and taking me back to the airport at 5:15 in the am on the day I left. I used a shuttle because I was way to tired after an 11 hour flight to try to figure out a train or bus. In my case the cost did not outweigh the convenience of being picked up and taken straight to my hotel. Rick's directions are fairly clear, but there are some of us that prefer not to try to navigate unfamiliar transportation after travel. After a week in Paris, I felt comfortable enough to have a taken the train to the airport, but I left too early to do so.

You can also take a taxi from CDG to your hotel, beginning in March they will be a flat rate, like in Rome airport (FCO). You can also use Uber X, it is the legal service in Paris. Taxis G7 is also a good company,http://www.taxisg7.com, they have English speaking operators, you can order the night before by calling them, going on line or using their App.
Enjoy your trip.

I have been taking RS tours and some of them started in Paris. I agree with Frank, look into taking the bus and if the bus does not stop near your hotel then take a cab the rest of the way. I have taken the bus from the airport to the bus stop near my hotel and it was fine. About 17Euro one way. Best way to get into Paris and easy! My hotel arranged for a shuttle to take me to the airport and that worked out fine too. But I don't care to take a shuttle from the airport to the hotel as I tried that and they did not show up.

I took the bus to Opera. From there I took the Metro to my hotel. I reversed the process going back. Easy peasy.
Two things to help you. The Google maps app has a public transportation section that can guide you.
I also have a solution for off line. Last time I used the MetrO app which is free. I downloaded the train, bus, and metro schedules ahead of time. The MetrO app works well off line. Find the name of the metro stop nearest your hotel and just dial it in. Metro tells you the color of the line plus the direction plus the name of the train. It's hard to mess up.

http://metro.nanika.net

I've found both Les Cars and Roissy Bus easy to use. In the case of Roissy, I got off at Opera and took a cab the short remainder of my trip and reversed the process going back to CDG. I think taxi drivers are used to this--when I told my driver "Opera", he automatically dropped me off near the bus stop.