EnemyAi script

var distance:float;
var target : Transform;
var lookAtDistance : float = 15.0;
var attackRange = 10.0;
var moveSpeed = 5.0;
var damping = 6.0;
private var isItAttacking = false;

    function Update () 
    {
    distance = Vector3.Distance(target.position, transform.position);
 
    if(distance < lookAtDistance)
    {
    isItAttacking = false;
    renderer.material.color = Color.yellow;
    lookAt ();
    }   
    if(distance > lookAtDistance)
    {
    renderer.material.color = Color.green; 
    }
    if(distance < attackRange)
    {
    attack ();
    }
    if(isItAttacking)
    {
    renderer.material.color = Color.red;
    }
}
 
 
function lookAt ()
{
var rotation = Quaternion.LookRotation(target.position - transform.position);
transform.rotation = Quaternion.Slerp(transform.rotation, rotation, Time.deltaTime * damping);
}
 
function attack ()
{
    isItAttacking = true;
    renderer.material.color = Color.red;
 
    transform.Translate(Vector3.forward * moveSpeed *Time.deltaTime);
}

i wrote these codes and i take this error

Assets/Standard Assets/Scripts/Utility Scripts/MeshCombineUtility.cs(177,30): warning CS0618: UnityEngine.Mesh.SetTriangleStrip(int[], int)' is obsolete: Use SetTriangles instead. Internally this function will convert the triangle strip to a list of triangles anyway.’
i’m new please help.

The error is not in your script. It is in Assets/Standard Assets/Scripts/Utility Scripts/MeshCombineUtility.cs, as you can see from the first line of the error message. You can try to fix the error by changing SetTriangleStrip to SetTriangles. If you do not need any of the standard assets, you could also just delete the entire standard assets folder; be careful and make sure nothing your project needs is in the folder if you choose to do this though.