Paris cdg to bayeux by train

This website shows the schedules. From the airport, take the RER "B" to Gare du Nord, then RER "E" to Gare St-Lazare, then an Intercity train to Bayeux. No need for TER unless you want to change trains again. No need for a reservation or advance ticket purchase.

This website has loads of detail about RER and Metro in Paris, and this one about train travel generally throughout Europe, including the trip you want.

At Gare St. Lazare, there is a ticket office in the corner of the station that handles the train tickets to Normandy. As I recall, it even says "Normandy Trains" over the office.

Also be aware that Gare du Nord is a Huge train station, so allow time to walk thru it to find the train to Gare St. Lazare.

We did this train trip a few years ago.
Gare St. Lazare to Bayeux. It required a change of train in Caen, but no problems.
When we arrived in Bayeux we even walked into the main part of town to our hotel, the Hotel Churchill.
We looked up all our train connections and options on the internet and had no problems.
Happy Travels.

A simpler way to get from CDG to the Gare Saint-Lazare station is to take the RoisseyBus (€12/pp). It leave right outside of arrivals, and drops you next to the Opéra Garnier. From there it is a 7-minute walk to Gare Saint Lazare. And there are is no changing of trains, no tunneling underground, and no stairs or escalators.

Thank you for your responses. So we don't need to buy tickets in advance? We are going the end of the month. When I get on the different websites that have the train information sncf trainline tickets are quite expensive. One thing that might be our problem is that we are coming to Paris on a Sunday. Any one out there have specific information about buying ahead as well as Sunday being a problem day and more expensive?

thank you so much!

plant

First off, SNCF runs the trains, so I personally see no reason to buy tickets from anyone but them:

https://www.sncf.com/en

Secondly, the problem with buying tickets ahead of time, is you can't be sure exactly when your flight will arrive, and how long it will take to get through immigration (if traveling from overseas), luggage, customs, and then to Gare Saint-Lazare. That being said, I usually buy a ticket ahead of time at least three hours from planned arrival. If I get there early, I soak up the ambiance of Paris in a café close to the train station. If I'm late, oh well. It hasn't happened yet, but I figure if the ticket is that much cheaper by buying ahead, it's a worthwhile gamble. If the tickets are already expensive, I'd just buy when there for the next available train.