You got your first job and as a taxi driver you earn more if you are able to get more passenger. As long as you have time, you would earn more in a single day. That is a pretty descent job and you can't go out and be choosy with your job since times are hard and it is not easy to find a job. What you need to right now is to find a passenger and make money not only for the operator, but yourself as well. This is a hard job, sure, but nothing is easy in this life, so we need to doing our job very well, if you want to stay with your job.
Each level would have a different mission that you need to fulfill to get to the next level. The summary of the mission is to take the passenger to their desired location. Of course, you don't want to bump into something since that would damage the car and it would cause you money. You would need to have it repaired as you would not be able to continue with the game if your cab is all bang up. The game gets more challenging as you make some progress.