C sharp beginner problem.

Can anyone help me I m a beginner in c sharp . I want the cube to travel particular distance I wrote this script to add a force but I want it to travel particular distance.this is my code

Public float velocity = 4f ;

Void Update() {

transform.postion += transform.forward * Time.delta time * velocity ;

}

Can anyone tell me how to impliment distance .

public float velocity = 4f ;
public float distance = 10f ;

private void Update()
{
    float delta = Mathf.Min( Time.deltaTime * velocity, distance );
    distance -= delta;
    transform.postion += transform.forward * delta ; 
 }