What is the best way to avoid AI collision with my script?

I'm trying to make an AI script that performs zombie-like actions, but I'm running into a few problems. The first problem I had was that when I used transform.position = Vector3.MoveTowards(); to move the AI directly to the player (since I do not want the zombies to roam around, I want them to come directly towards the player),the two AI that I have run into each other and it seems as if they are transparent. I tried to fix this with a code from a tutorial I found by using way points. However, when I use the way points, the AI just stays in place and never moves. So, with the code below, what would be the best approach to this problem? I would like to learn how to code an AI, so please don't recommend programs to me. What I would like the AI to do is follow the player and move around obstacles in order to get to the player.

 @script RequireComponent(CharacterController)
 public var wayPoints : Waypoints;
 //Animations//
 public var _animation : Animation;
 public var runAnimation : AnimationClip;
 public var runAnimationSpeed : float = 2.0;
 public var idleAnimation : AnimationClip;
 public var idleAnimationSpeed : float = 1.0;
 //Get player... might be an array in the future.//
 public var player : Transform;
 public var AI : Transform;
 //Ragdoll//
 public var death : GameObject;
 //Movement Speeds//
 public var rSpeed : int = 9;
 public var wSpeed : int = 2;
 //Vectors//
 public var v3_targetDirection : Vector3;
 public var v3_moveDirection : Vector3;
 //Get Distance from character to player//
 public var distanceAway : float;
 //More Speeds//
 private var f_verticalSpeed : float = 0.0;
 private var f_moveSpeed : float = 0.0;
 //Health//
 public var aiHP : float = 100;
 private  var aiMaxHP : float;
 //Character Controller//
 private var controller : CharacterController;
 //Collison Flag//
 private var c_collisionFlag : CollisionFlags;
 //Movement Speeds//
 private var f_movementSpeed : float = 0.0;
 //Booleans//
 private var b_isStop : boolean;
 private var b_isAlive : boolean;
 //rotate//
 private var f_rotateSpeed : float = 1.2; //Smooth speed of rotation
 //weapon//
 var weapon : Rigidbody;
 var throwSpeed : float;
 
 
 function Awake() {
 controller = GetComponent(CharacterController);
 b_isAiming = false;
 b_isStop = false;
 b_isAlive = true;
 c_collisionFlag = CollisionFlags.CollidedBelow;
 aiMaxHP = aiHP;
 
 _animation[runAnimation.name].speed = runAnimationSpeed;
 _animation[runAnimation.name].wrapMode = WrapMode.Loop;
 _animation[idleAnimation.name].speed = idleAnimationSpeed;
 _animation[idleAnimation.name].wrapMode = WrapMode.Loop;
 
 
 
 }
 public function GetHpPercent() : float {
     return aiHP/aiMaxHP;
 }
 
 
 
 function Start () {
 transform.position = wayPoints.StartPosition();
 }
 
 function Update () {
 var v3_targetDirection : Vector3 = wayPoints.GetDirectionToPlayer(transform, player);
 GetHpPercent();
 _animation.CrossFade(runAnimation.name);
 if(aiHP <= 0){
 b_isAlive = false;
 }
 
 if(b_isAlive == true){
 distanceAway = GetDistance(AI, player);
 }
 if(distanceAway <= 5){
 
 _animation.CrossFade(idleAnimation.name);
 /*
 var  newProjectile : Rigidbody = Instantiate(weapon, AI.position, AI.rotation);
 newProjectile.rigidbody.velocity = transform.forward * throwSpeed;
 */
 rSpeed = 0;
 }else{
 rSpeed = 9;
 _animation.CrossFade(runAnimation.name);
 }
 if(v3_targetDirection != Vector3.zero){
 v3_moveDirection = Vector3.Slerp(v3_moveDirection, v3_targetDirection, f_rotateSpeed * Time.deltaTime);
 }
 var v3_movement : Vector3 = (v3_moveDirection * f_moveSpeed) + Vector3 (0, f_verticalSpeed, 0); // Apply the vertical speed if character fall down
 v3_movement *= Time.deltaTime;
 
 controller.Move(v3_movement);
 if(v3_moveDirection != Vector3.zero)
 {
 transform.rotation = Quaternion.LookRotation(v3_moveDirection);
 Debug.Log("You're moving!");
 }
 
 }
 
 function GetDistance (_AI : Transform, _player: Transform) {
 var distance : float = Vector3.Distance(_AI.transform.position, _player.transform.position);
 return distance;
 }
 
 
 function OnTriggerEnter(col : Collider){
 if(col.tag == "EnergySaw"){
 aiHP -= 20.0;
 if(aiHP <= 0){
 aiHP = 0;
 var ragdollPrefab : GameObject = Instantiate(death, transform.position, transform.rotation);
 
 }
 }
 }
 
 public function OnDrawGizmos() : void {
     if (player != null) {
         Gizmos.color = Color.blue;
         Gizmos.DrawLine(transform.position, player.position);
     }
 }

It's a lot of code, sorry about that. Thank you in advance!