Charles De Gaulle to Bayeax

First, a correction, it is spelled Bayeaux.
It certainly is doable. Train to Paris and then another train to Bayeaux. Bayeaux is such a beautiful town, not bombed.

Another correction :

It's spelled Bayeux.

Say your plane arrives on time. One can usually assume it's 9:30 by the time you get out of the front door of the airport either to a taxi or the RER into Paris.

A taxi will be 56€ to the Gare St Lazare for up to four people and your luggage. Going will be slow at that time of morning, but you will make it after maybe an hour or more likely 90 minutes.

So now it's 11 am.

Now you need to find the next train leaving the station for Bayeux. It takes something like two hours and 20 minutes. Buy tickets on the machines in the station, or set up an account on SNCF Connect ahead of time and buy them there.

Tickets should be around 50€ a person.

Whether you can make a meeting point by 2 pm depends on a lot of factors, including whether your plane arrives on time, how long it takes you to get through immigration, whether you have to pick up checked luggage, how long the taxi line is, how long the ride takes, how long it takes you to find your way in the station, how easy you find it to buy four tickets, and the time of the next departing train for Bayeux.

I will say it's an ambitious plan.

It’s a very ambitious plan with little room for error. You need to catch the 10:59 train to Bayeux to arrive before 2. Are you traveling in the front of the plane? Will you have to go through passport control? Do you have checked luggage? A group moves as slowly as its slowest member. Are the four of you seasoned efficient travelers? The usual advice is to allow four hours between ETA at CDG for the flight and departure time for a train leaving from central Paris. This could all work out but IMO your best plan is a private tour the next day but then again, I hate rushing around trying to meet tight timelines while on vacation. Depending on whether jet lag is a factor, you could consider renting a car and driving, which should take about 3.5 hours if there are no major traffic issues. Of course, you would have to be on the road by around 10:00 to make the car rental work and the last time I rented at CDG, it took over an hour for us to get the car. So, I reiterate: it seems that the best suggestion is to change the date of the tour or change your flight to the day before.

Thanks everyone. We’ve abandoned this idea, planning a relaxing rest day in Paris.

Great idea. Your original plan was setting you up for failure and who wants to start a trip with having missed the first planned event? Safe (and fun) travels.