Steal a taxi and start driving it around until you are assigned a job by the dispatch operator. Accept the job and follow the GPS path to reach the waiting customer. After picking up the customer, take a roundabout route to the requested destination. Your passenger will have to pay for the ride according to the distance driven, even if the fare winds up in excess of $1000 because you went joyriding. This is an easy way to make money near the beginning of the game.