How do you add car movement and steering wheel joystick?
What kind of answer do you expect here? - This is such a broad question…
Setting up a car requires: a visual car model, wheel colliders, a rigidbody and a script to get the input and set the input as steeringangle and forward torque for the wheel colliders.
There are tons of tutorials on various tutorial-websites on how to do cars in Unity. there are tons of videos on this on youtube. Did you try researching this? If so what did you fail on? What did you even try? What was the specific problem that you struggled with?
Is there code that you wrote that you can share so that we can see what you already did? Please be more specific about your question.