From what I remember it's an HLS and not much more. I don't think there's fuel or hangarage. The airfield to the west of Cannes is Mandelieu, and has facilities.
Heli Securite based in St Trop use JCA for all the big Cannes festivals, so they are bound to know the contact info etc. +33 494 555 999
Azure Helicopters are based at Cannes Mandelieu and must also know the info - they are on +33 4 93 90 40 70