Quick Help with some basic things x)

public class Destroy : MonoBehaviour
{
    public GameObject Square;

    // Start is called before the first frame update
    void Start(){
        Square.SetActive(true);        
    }

    // Update is called once per frame
    void Update(){
        if(Input.GetKeyDown("up")){
        Square.SetActive(true);
        }
        if(Input.GetKeyDown("down")){
        Square.SetActive(false);
        }
    }
}

public class Destroy : MonoBehaviour
{
    public GameObject Square;

    // Start is called before the first frame update
    void Start(){
        Square.SetActive(true);        
    }

    // Update is called once per frame
    void Update(){
        if(Input.GetKeyDown("up")){
        Square.SetActive(true);
        }
        if(Input.GetKeyDown("down")){
        Square.SetActive(false);
        }
    }
}