Transportation from Nice airport to Avignon

You could take the train from Nice to Avignon both have train stations.
Tickets for June will be available for purchase after February 12, 2025. via the SNCF website:
https://www.sncf-connect.com/en-en

Train is easy.. We did this trip a while back. You can also take a bus but it's longer. There a 2 train stations in Avignon. Gare Avignon Centre is the closest to where the boats tie up. About a 10 minute walk. The train was a lovely ride. We took the train along the coast through Antibes and Cannes to Marseille then changed trains in Marseille to Avignon Centre. The Train stops at Avignon TGV station but if you want to stay in the town itself, you need to buy your ticket to Avignon Centre. Once at the TGV you will get off and catch the next train to Avignon Centre which is a 5 min. ride. There are also non stops, depending on time of day. It's anywhere from a 3 to 3.5 hr. ride, depending on train. Some of the trains will go straight to Centre. Again, depends on which time of day and which train you select. Either way, it's an easy trip. Check out www.trainline.com and plug in your dates and see your options or www. scnf-connect.com. You can purchase tickets at either site. We stayed at the Ibis Styles Nice Centre Gare which is by the train station in Nice (Nice Ville). Great hotel, excellent reviews, and walkable to the sites. https://all.accor.com/hotel/9907/index.en.shtml
We took an Uber from the airport to the hotel, but there is a Tram that also runs to Nice Centre. We walked to the shoreline, the Promenade, and Old Nice. It was an enjoyable visit. Book your train from Nice Ville to Avignon Centre.

Molly, I am not surprised your cruise line won't pick you up in Nice to get to the boat., Nice is 162 miles from Avignon.