I used to be a marble/granite mason and fitted many of these worktops in granite.
They will last forever with hardly any care.
keep anything off the surface that may rust, rust stains are lethal, also beware of hardwood like oak for instance if left in the same place on a piece of granite, it will stain the granite if it becomes wet.
Always use a chopping board, whilst granite is extremely tough and hard-wearing, constant cutting and scratching will take its toll.
Avoid banging anything hard on the corners and edges to avoid chipping.
You are unlikely to damage any granite worktop with day to day use, just keep it clean and keep untreated metals and hardwoods away from it and it will last a lifetime without any deterioration.