You'll be paid the base fee plus the actual time and distance of the ride. This means your earnings are not affected if the first passenger does not match with another passenger.
The ride price for passengers, on the other hand, is calculated differently. Passengers are given a fixed price when they place their ride request based on the estimated time and distance of the trip, and the probability of matching with other passengers.
Sometimes you will only pick up one passenger and we will lose money on the ride; other times, you will pick up multiple passengers and we will earn money on the ride.