I'm following (Brackeys) on YouTube, and I can get my object to go forwarde but it's not going sideways. Dose he do good codes?

Question

unity UnityEngine;

public class move : MonoBehaviour{

public Rigidbody rb;

void FixedUpdate ()
{
rb.AddForce (500, 0, 0 * Time.deltaTime);

if (input.GetKey (KeyCode.A)) {

rb.AddForce(0, 0, -500 * Time.deltaTime);

if (Input.GetKey (KeyCode.D)) {

rb.AddForce (0, 0, 500 * Time.deltaTime);
}
}
}
}

Answer 1

You should specify the event if it's pressing the button stopping
if(input.GetKeyDown(KeyCode.A))
Or you can use
if(input.GetKey("a"))

Answer 2

Instead of adding a force to the rigidbody, It sounds like what you want is changing the velocity. Try:
rb.velocity = // the code here