Move enemy ship down while moving left and right

so I’m new at unity and I’m starting off a simple space shooter. I made some enemy ships fly downward but I want to vary it up by making some fly downward but swaying left and right. If I can get some help on writing a script for that, it would be great. I use java for scripting. Thanks and I go to this community site to get answers on things I need help on. Great community!

I added to your script to make the ship sway as it descends. You can set swaySpeed and swayMagnitude in the inspector.

#pragma strict
public var speed = 2.0f;         //Move speed
public var swayMagnitude : float = 0.3f;
public var swaySpeed : float = 3.0;
 
function Update () {
   var v3T : Vector3;
   v3T.x = Mathf.Sin(Time.time * swaySpeed) * swayMagnitude;
   v3T.y = transform.position.y - speed * Time.deltaTime;
   v3T.z = 0.0;
          
   transform.position = v3T;

   if (transform.position.y < -15) {
     //Destroy
     Destroy(gameObject);
   }
}

not tested but you can give it a try

var speed : float = 2.0f ;

function Update (){

transform.Translate(Vector3.down * speed  * Time.deltaTime);

if(transform.position.y =< -10){
transform.Translate(speed * Time.deltaTime , -1 * speed * Time.deltaTime, 0);
}
}