How can I make a prefab object from a list to move?,How can I make an object from a list to move by itself?

So, I have a list of prefab objects and i randomly instantiate them at an fixed y axis position and i need them to move till -70. The problem is that I don't know which one will be spawned. Tried this:

 Enemies[Random.Range(0, 8)].transform.Translate(Vector3.forward * Time.deltaTime * -5f, Space.Self);

but dosen't work... This is my script so far:

 public class Enemy : MonoBehaviour
 {
     public float spawnRate = 1f;
 
     private float nextTimeToSpawn = 0f;
 
     public List<GameObject> Enemies;
 
 
 
 
     // Update is called once per frame
     void Update()
     {
         Enemies[Random.Range(0f, 8f)].transform.localScale = new Vector3(Random.Range(50f, 100f), Random.Range(50f, 100f), Random.Range(50f, 100f));
         Vector3 position = new Vector3(Random.Range(-8f, 8f), -20f, Random.Range(-4f, 5f));
         Enemies[Random.Range(0f, 8f)].transform.Translate(Vector3.forward * Time.deltaTime * -5f, Space.Self);
         if (Time.time >= nextTimeToSpawn)
         {
             Instantiate(Enemies[Random.Range(0f, 8f)], position, Quaternion.identity);
             nextTimeToSpawn = Time.time + 1f / spawnRate;
         }
         
     }
 }

,So, I have a list of objects, they are instantiated randomly at a fixed y axis position, and i want them to move on y axis by them-self. I tried this: Enemies[Random.Range(0, 8)].transform.Translate(Vector3.forward * Time.deltaTime * -5, Space.Self); Enemies is the list of prefab objects and because i don't really know which one is going to be instantiated I used Random.range but they are not moving.