which force i will use and where to add the force?
This is a pretty big question, and you might be better served looking up how to do vehicle physics via Google first, and read the many many articles about that subject. If you are looking for specific support, there are several package on the Asset Store which provide vehicle physics without having to code it up yourself. Good luck!
Basic moving objects is not much difficult. But you should consider more forces for vehicle body. There is a official example for vehicle physics from Standard Assets of Unity. I think that’s good start.
i am using motortorque is that true and something else and my car is tilting when he gain speed.
sorry for bad english
Try changing settings of your wheel colliders. You can refer official sample project of Unity.