SImple Movement

Hi! Really starting Newbie here

I want to move my character ONLY forward when W key is pressed
so I made this script to character only go forward

anyone can kindly tell me why this script having error?

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerMovement : MonoBehaviour
{

public CharacterController controller;
public Animator anim;
public float speed = 12f;

void Update()
{
    anim.SetFloat("Verti", Input.GetAxis("Vertical"));
    anim.SetFloat("Hori", Input.GetAxis("Horizontal"));

    float x = Input.GetAxis("Horizontal");
    float z = Input.GetAxis("Vertical");

    Vector3 move = transform.forward * z;

    if (move <= 0)
    {
        move = 0;

    }
    else {
                             
        controller.Move(move * speed * Time.deltaTime);

    }

    
}

}

You can’t compare Vector3 and int, or assign an int to a Vector3. Try changing the if statement to:

if(z <= 0f)
{
    move = Vector3.zero;
}
else ...

Hope this helps!