The cars you can buy with the money you are given at the start of the game are not too fast. Instead of racing people at night, which does not give you any money at first, concentrate on the first set of day races. Get first place in each race to unlock the second category of races. Repeat this until you can race in Class 3. You will then be able to make about 1,000,000cp per day. If you skip night racing for about the first ten days and only race during the day, you will be able to amass around 10,000,000cp and buy yourself a very good car.