Welcome to TheTravelzine again.
Yes, Provins is worth visiting and you can get there by train (departure from Gare de lŽEst).
You can spend a day there and I can recommend a nice restaurant, located in the upper town. If you go there on a beautiful spring day, you can eat outside. I'll try to find the name and send it soon.
Seine et Marne is a region where you can find very nice medieval cities.
Try to give you more information later.
Regards and enjoy your trip to France.
Pierrette (Dresden, Germany)