Simple AI In 2D - C#

Im making a simple free roam spaceship game, and all i need is the alien to move towards me, i only know how to do this in 3d, ive sorted out the rotation bit(with help) so it always points towards me, but how can I make it move towards me, because at the movement im telling it to go foward , but our Z angles are equal?? Can i make it so that it follows my X+Y?? Just Look :

 using UnityEngine;
 using System.Collections;
 
 public class EnemyAI : MonoBehaviour {
     public Transform target;
     public int moveSpeed;
     public int rotationSpeed;
 
     private Transform myTransform;
 
     // Use this for initialization
     void Awake() {
         myTransform = transform;
     }
 
     void Start () {
         GameObject go = GameObject.FindGameObjectWithTag("Player");
 
         target = go.transform;
     }
     
     // Update is called once per frame
     void Update () {    
         Vector3 dir = target.position - myTransform.position;
         dir.z = 0.0f; // Only needed if objects don't share 'z' value
         if (dir != Vector3.zero) {
             myTransform.rotation = Quaternion.Slerp (myTransform.rotation, 
                                                      Quaternion.FromToRotation(Vector3.right, dir), rotationSpeed * Time.deltaTime);
         }
 
             //Move Towards Target
         myTransform.position += myTransform.position * moveSpeed * Time.deltaTime;
     
     }
 }