Player Movement in Unity 3D

Question

So I am new at Unity and I am following a YouTuber named Brackeys but when I execute his code for movement of the character my character doesn't go forward or backward it does go Left and Right but in super speed. I am new at this so I don't know much about this. Here is the code :

using UnityEngine;

public class PlayerMovement : MonoBehaviour {

public Rigidbody rb;

private float forwardForce = 2000f;  
public float sidewaysForce = 500f;  

void FixedUpdate()
{

    rb.AddForce(0, 0, forwardForce * Time.deltaTime);

    if (Input.GetKey("d"))  
    {

        rb.AddForce(sidewaysForce * Time.deltaTime, 0, 0, ForceMode.VelocityChange);
    }

    if (Input.GetKey("a"))  
    {

        rb.AddForce(-sidewaysForce * Time.deltaTime, 0, 0, ForceMode.VelocityChange);
    }

    if (rb.position.y < -1f)
    {
        FindObjectOfType<GameManager>().EndGame();
    }
}

}

Answer 1

I think what you are missing here is movement along z axis.

    if (Input.GetKey("w"))  
    {

        rb.AddForce(0, 0, forwardForce * Time.deltaTime, ForceMode.VelocityChange);
    }

    if (Input.GetKey("s"))  
    {

        rb.AddForce(0, 0, -forwardForce * Time.deltaTime, ForceMode.VelocityChange);
    }