I booked a roundtrip ticket on the TGV train from Paris to Champagne for 56.50 euros, or about $62. I purchased the tickets via Rail Europe, which I think is the easiest way for Americans to buy train tickets in advance.
I recommend getting to the station about 15 minutes before your train’s departure so that you have ample time to find your seat. Tickets are either first- or second-class, and each ticket has a coach number and seat number attached.
To access the train platform, I had to scan a QR code. But keep your phone handy — the conductors came through the cabin to scan it again during the ride.
Since TGV is France’s high-speed rail, the trip only takes about 40 minutes.
I got off in Reims, the largest city in the Champagne region. French kings used to be crowned at the Cathédrale Notre-Dame de Reims, and today, many Champagne houses are headquartered there.