How to respawn enemies after one is destroyed?

So I am doing this simple arcade style shooter game. My problem is that I know once my laser hits the enemy object it should get destroyed but once it get destroyed it is gone forever. I want to know how can I have a continuous enemy objects come at my spaceship even if it is destroyed. Its a 2d game but when I set up my game I followed the official unity3d beginner space shooter tutorial. In that tutorial coroutine were used but I am doing mine a bit differently. Here is how my code looks

using UnityEngine;
using System.Collections;

public class Enemy : MonoBehaviour {

	Transform myTransform;
	public int minSpeed;
	public int maxSpeed;
	int x,y,z;
	public int currentSpeed;

	// Use this for initialization
	void Start () {
		x = -7;
		y =  0;
		z = 14;
		myTransform = transform;
		myTransform.position = new Vector3(x,y,z);
		currentSpeed = Random.Range(minSpeed,maxSpeed);
	}
	
	// Update is called once per frame
	void Update () 
	{
			x= Random.Range(-12,12);

			myTransform.Translate(Vector3.back * currentSpeed * Time.deltaTime);
			//everytime the enemy object goes beyond z=-6 it dissapears and creates a new enemy object
			if(myTransform.position.z < -6)
			{
				myTransform.position = new Vector3(x,y,z);
				currentSpeed = Random.Range(minSpeed,maxSpeed);
			}
	}
	void OnTriggerEnter(Collider collider)
	{
		if(collider.gameObject.CompareTag("Projectile"))
		{
			Destroy(this.gameObject);
		}
	}
	
}

Now, there wasn’t too much info that you provided us with for us to give a solid answer, but I’d say use the Instantiate method. Here’s an example of it in use:

void OnTriggerEnter (Collider collider) {

if(collider.gameObject.CompareTag ("Projectile")){
//Right now, all you have is this
Destroy(this.gameObject);
//If you add this, it should instantiate a new enemy prefab
Instantiate(EnemyPrefab, EnemyPrefabPosition, Quaternion.identity);
//the quaternion is just to show that there's now rotation
//I used placeholder names as well.
//Check the scripting reference for Instantiate for more info.
}

}