Arriving in Nice in late May. What is the most practical way to get from the Nice airport to Cannes?
Take the train , you wil be there in 30-40 minutes
Nice airport does not have a railway station in the airport area - you need to either make a fairly long walk to the St Augustin station or get a bus or cab into central Nice. The regional bus route 210 operates along the motorway to Cannes - times and fares are at https://www.departement06.fr/documents/Import/servir-les-habitants/210.pdf
There is a small train station in port Saint Laurent which is about a 5-10 minute bus ride from the airport . . My wife and I stayed at a holiday inn by the marina in port Saint Laurent and we walked
to the station and our hotel was no more than a 10 minute ride to the airport . You can see the airport runways . Try using google earth and you can see the area .