I just bought a new car. How to maintain it?

General car maintenance is the first maintenance within three months or after driving 5000 kilometers. If it is a new car, it will be within 5000 kilometers within three months, because there is a lot of iron nitrate in the new car after running-in. Is it good or bad to replace it first? The service life of engine oil is three months. If it exceeds three months, the probability of deterioration will be accelerated, and the lubrication program will not start, which is not good for the car.