how to make player move where you are looking

how would i make my script always move my character where it is looking. here is my script, it is for mobile btw.

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

[RequireComponent(typeof(CharacterController))]

public class SC_FPSController : MonoBehaviour
{
    public float walkingSpeed = 7.5f;
    public float runningSpeed = 11.5f;
    public float jumpSpeed = 8.0f;
    public float gravity = 20.0f;
    public Camera playerCamera;
    public float lookSpeed = 2.0f;
    public float lookXLimit = 45.0f;
    public float distance = 5;

    CharacterController characterController;
    Vector3 moveDirection = Vector3.zero;
    float rotationX = 0;

    

    void Start()
    {
        characterController = GetComponent<CharacterController>();
        
        

    }

    void Update()
    {
        // We are grounded, so recalculate move direction based on axes
       
       
        float movementDirectionY = moveDirection.y;
        

        if ((Input.GetButton("Jump") || SC_MobileControls.instance.GetMobileButtonDown("Jumping")))
        {
            moveDirection.y = jumpSpeed;
        }
        else
        {
            moveDirection.y = movementDirectionY;
        }

        // Move the controller
        characterController.Move(moveDirection * Time.deltaTime);

        // Player and Camera rotation
       
        {
#if UNITY_IPHONE || UNITY_ANDROID || UNITY_EDITOR
            rotationX += -(SC_MobileControls.instance.GetJoystick("JoystickRight").y) * lookSpeed;
#else
            rotationX += -Input.GetAxis("Mouse Y") * lookSpeed;
#endif
            rotationX = Mathf.Clamp(rotationX, -lookXLimit, lookXLimit);
            playerCamera.transform.localRotation = Quaternion.Euler(rotationX, 0, 0);
#if UNITY_IPHONE || UNITY_ANDROID || UNITY_EDITOR
            transform.rotation *= Quaternion.Euler(0, SC_MobileControls.instance.GetJoystick("JoystickRight").x * lookSpeed, 0);
#else
            transform.rotation *= Quaternion.Euler(0, Input.GetAxis("Mouse X") * lookSpeed, 0);
#endif
        }
    }
}

If you use a Vector3.forward as your direction component, the object will move in the direction it is facing.