1) do everything you can to dry the electronics, DO NOT START THE CAR. wait for a few days.
2) find or get help to access the car’s computer box. this box gets fried when the car is started when it is wet.
3) if car’s computer box is dry, check your oil and auto transmission dipsticks for water contamination. if the car has never been started, water and oil remain separate and easy to see. if car has been started, water will turn the motor oil to look like chocolate milkshake, or strawberry milkshake (for auto transmission fluid). car remains driveable, but needs an oil change badly.
4) if you suspect your fuel tank to be contaminated too, drain and replace fuel. normally, the tanks dont get penetrated, it is a fully sealed system.
5) start and drive to the nearest service station to change all fluids and bearing grease or as recommended.
6) the rest of the car can survive. carpets, upholstery, etc etc. car detailing will help restore the freshness. accessories can be replaced.