Great place at the beach in Nice to have lunch is Le Galet. It is right on the beach, right on the Promenade des Anglais. It is always crowded because you sit right on the sand, the food is delicious, and the setting is incredible. The prices? Very expensive.
Think New York, but very posh, very elite. You have to make a reservation absolutely in advance. It is always crowded, but you feel like you are in St. Barths. The location and views are unbeatable—right on the water.
If you don’t book ahead, you won’t get in. Make a reservation well in advance.
It's also a beach club where you can rent sun loungers and beach beds for the day.
https://www.galet-plage.com/en/index
3 Prom. des Anglais, 06200 Nice, France
La Galet / Official Site