If the coating has cured correctly according to the ceramic coatings manufacturer’s directions, you should be getting beautiful beads or water sheeting where the water just falls off the car.
However if the car got wet before the initial cure time has past it may create some blemishes which will need to be rectified and re-applied to ensure the installation and durability is unaffected.
Most coatings are touch dry within a few hours and the complete curing time is usually a few days up to a week. While most coatings can get wet the next day after being applied even during the final curing stage, it is usually advised not to wash or apply significant pressure to the coating during this time.