Targetting Script Help

Hi Guys :D I Have a question. Is it Possible to Change this script so I "Target" a Enemy when i click on it :). I need Just Help with it to. :) So Here is the Script:

public class Targetting : MonoBehaviour { public List targets; public Transform selectedTarget;

 private Transform myTransform;
     
 void Start () {
     targets = new List<Transform>();
     selectedTarget = null;
     myTransform = transform;
     
     AddAllEnemies();
 }
 
 public void AddAllEnemies() {
     GameObject[] go = GameObject.FindGameObjectsWithTag("Enemy");
     
     foreach(GameObject enemy in go)
         AddTarget(enemy.transform);
 }
 
 public void AddTarget(Transform enemy) {
     targets.Add(enemy);
 }
 
 
 private void SortTargetsByDistance() {
     targets.Sort(delegate(Transform t1, Transform t2) {
             return Vector3.Distance(t1.position, myTransform.position).CompareTo(Vector3.Distance(t2.position, myTransform.position));
             });
 }
 
 private void TargetEnemy() {
     if(selectedTarget == null) {
         SortTargetsByDistance();
         selectedTarget = targets[0];
     }
     else {
         int index = targets.IndexOf(selectedTarget);
         
         if(index < targets.Count - 1) {
             index++;
         }
         else {
             index = 0;
         }
         DeselectTarget();
         selectedTarget = targets[index];
     }
     SelectTarget();
 }
 
 private void SelectTarget() {
     selectedTarget.renderer.material.color = Color.red;
     
     PlayerAttack pa = (PlayerAttack)GetComponent("PlayerAttack");
     
     pa.target = selectedTarget.gameObject;
 }
 
 private void DeselectTarget() {
     selectedTarget.renderer.material.color = Color.white;
     selectedTarget = null;
 }
 
 // Update is called once per frame
 void Update () {
     if(Input.GetKeyDown(KeyCode.Tab)) {
         TargetEnemy();
     }
 }

}

Any Ideas to Start or Help :)?