We would like to travel back to Paris from Nice via train. We'd hope we would be able to spend a little time in Provence. We can't seem to figure out the best way to do so. I've attempted to use the sncf site, but when I change the language to English, I'm told I'm unauthorized to view the page. When I attempt the TGV link on this site, it converts to sncf. I need your guidance. Please and thank you!

As is the case of this type of posting, the crucial info is missing. What is the URL of the "sncf" site you are looking at?
The site to lookup schedule and buy tickets is www.oui.sncf
If you are just looking at the schedules, www.bahn.com is much easier to use. You cannot buy tickets at bahn site, however.

Thank you!

Or just use www.trainline.eu. It seems to be easier for anglophones, and it's an official affiliate of the most popular European rail networks, so the schedules and prices are the same. And yes, you can buy and print out your tickets right from their site.

There must b e something wrong with your computer as the SNCF website never tells someone they are "unauthorized" to view it just because they change the flag to English. Which they don't really have, anyway, they have flags for countries, not languages. But if you change it to UK you get this
https://en.oui.sncf/en/

They used to divert you to Raileurope if you claimed you were not in France and couldn't read French, I think, but they don't seem to even do that anymore, as that page shows.

There isn't really any rail company called TGV, it's a train brand run by SNCF anyway. So that's why it converts to SNCF. They used to have their own website for some odd reason but I guess SNCF realized that was a waste of resources so now it converts to the regular website.

Take TGV Nice to Avignon TGV - rent a car and stay in some neat town like Arles or St-Remy-de-Provence and in a compact area you have so many neat sights or sans car stay in Arles or Avignon - two really neat old cities and take buses and trains to many places. Then off to Paris in about 3 hours or less. Yes www.oui.sncf is the site to book tickets on but as some experts above say www.trainline.eu has same fares and supposedly is easier to use.

There was an article in the French press this week saying that the Italian Thello train is better than the SNCF on this route. Although rail travel will be fully open to international competition by the end of 2019, at the moment there are very few foreign companies operating services on French soil.

www.thello.com does not show any Nice-Paris offerings but Milan-Marseille. It apparently is not running that route yet?

@PalenQ, yes, just to Marseilles on a regular train. (This year, Thello reached an agreement in PACA to allow TER subscribers to take the Thello trains as well, via a 3E supplement, an experiment in open markets before the official opening)

I would repeat the advice above -- take the train to Aix or Avignon, rent a car (or rent a car from Nice) and then continue on to Paris from Avignon after a tour of the countryside. Or, if you do not want to rent a car, take the train to Avignon. The transit connections into the countryside and the tour offerings are a bit better, I believe.

Depends on how much time they want to spend in Provence - and Avignon is the heart of tourist Provence - a few days I'd base in Avignon and maybe take an excursion or two or public transit to places convenient for that - but for several days a car rental IMO would be great and stay in a smaller town.

punchyb - How long do you have for your stop?

Avignon is worth a day's visit itself. The high-speed TGV stops outside the city with a five-minute shuttle to the old central station at the edge of the city walls. The TGV service from Nice is on a TGV train but not super-fast as the tracks won't support great speeds. It's a three-hour ride.
Site officiel de l'Office de Tourisme d'Avignon

So many here don't have much great to say about Avignon and stress going to villages and smaller towns to stay. But IME Avignon was a great place to stay - lots of folks out and about at night - amazing Palace of the Popes and of course the famous Pont d'Avignon of child song fame still standing half-broken across the river and a really old look and feeling inside the ramparts that still enclose much of it. And for folks sans car a great base for buses and trains. Arles too is a really neat city -smaller but neat - famous market and van Gogh and Cezanne copies of portraits set up where they painted them throughout the town. Short train ride from Avignon.

I understand you want to take the train...but just in case you change your mind, Air France has multiple nonstop flights daily to Orly for under $50 (dollars!), many as little as $41 at convenient times.

The flight time is 1:30. Of course you have 1:30 or so at the start (Nice airport is easy) and another hour or so at the end to deplane and get to the city center.

We did this a year ago, and it was easy. Something to consider.
SS

Plane would be cheaper than train but OP wants to stop off somewhere en route.