How to make the player move without user input

Hi, I’m making a game and I’m stuck on this for ages. How to make the player move in a certain direction without user input. Please, could you help me I’m new to Unity?

If you want your player to move without user input like in Subway Surfers or other runners you can try using Tranlate

Here is an example

public float speed = 10f;
private Vector3 dir;

void Start(){
     dir = Vector3.forward; //Vector3(0, 0, 1)
}

void Update(){
     float amountToMove = speed * Time.deltaTime;
     transform.Translate (dir * amountToMove);
}

For more information about Transform.Translate and others check Unity Scripting Reference