Nice is a big busy city with a great promenade along the beach. For relaxing--if you have a car---I would prefer Mougins or Biot or if you can afford it Chateau Eza in Eze Village.
Have a relaxing meal along the harbor in Cannes. Visit the Oceanographic Museum in Monte Carlo. Go see the great motor yachts in the boat basin in Antibes. Visit the enchanting hill villages like St. Paul de Vence.
I don't speak French---but in many trips there have never ever had a problem. The whole area is used to international tourism.