Hello, I have this piece of code and after coming back to my scripting days I have wanted to change it, I would really for the character to constantly move forward. I’m really sorry, could anyone help me with this? Code below 
This movement script is for moving around a planet (a sphere with its own gravity)
using UnityEngine;
using System.Collections;
[RequireComponent (typeof (GravityBody))]
public class FirstPersonController : MonoBehaviour {
// public vars
public float mouseSensitivityX = 1;
public float mouseSensitivityY = 1;
public float walkSpeed = 6;
public float jumpForce = 220;
public LayerMask groundedMask;
// System vars
bool grounded;
Vector3 moveAmount;
Vector3 smoothMoveVelocity;
float verticalLookRotation;
Transform cameraTransform;
Rigidbody rigidbody;
void Awake() {
Cursor.lockState = CursorLockMode.Locked;
Cursor.visible = false;
cameraTransform = Camera.main.transform;
rigidbody = GetComponent<Rigidbody> ();
}
void Update() {
// Look rotation:
transform.Rotate(Vector3.up * Input.GetAxis("Mouse X") * mouseSensitivityX);
verticalLookRotation += Input.GetAxis("Mouse Y") * mouseSensitivityY;
verticalLookRotation = Mathf.Clamp(verticalLookRotation,-60,60);
cameraTransform.localEulerAngles = Vector3.left * verticalLookRotation;
// Calculate movement:
float inputX = Input.GetAxisRaw("Horizontal");
float inputY = Input.GetAxisRaw("Vertical");
Vector3 moveDir = new Vector3(inputX,0, inputY).normalized;
Vector3 targetMoveAmount = moveDir * walkSpeed;
moveAmount = Vector3.SmoothDamp(moveAmount,targetMoveAmount,ref smoothMoveVelocity,.15f);
// Jump
if (Input.GetButtonDown("Jump")) {
if (grounded) {
rigidbody.AddForce(transform.up * jumpForce);
}
}
// Grounded check
Ray ray = new Ray(transform.position, -transform.up);
RaycastHit hit;
if (Physics.Raycast(ray, out hit, 1 + .1f, groundedMask)) {
grounded = true;
}
else {
grounded = false;
}
}
void FixedUpdate() {
// Apply movement to rigidbody
Vector3 localMove = transform.TransformDirection(moveAmount) * Time.fixedDeltaTime;
rigidbody.MovePosition(rigidbody.position + localMove);
}
}