How to move object from an array position to another array position?

Hi. I've just started learning to use Unity last month but currently have an assignment of building a game. I've created arrays as the fixed position of the objects. Now I'm trying to move object from the "eggPosition[5]" to a new position(eggPosition[6] = new Vector3(-2f,-4f);) by hitting "Z" key. I've read some tutorials about Vector3.movetowards , Vector3.lerp , Transform.position and etc. However, I still don't know how exactly should I use them. Anyone have a clue? Thanks in advance

 using UnityEngine;
 using System.Collections;
 
 public class EggSpawn : MonoBehaviour
 {
     public GameObject eggsPrefab;
     public Sprite[] eggSprites;
     public int x;
 
     public Transform positionLeft;
     public Transform positionRight;
 
     Vector3[] eggPosition = new Vector3[6];
 
     //egg position
     void Awake()
     {
         eggPosition[1] = new Vector3(0, 1f);
         eggPosition[2] = new Vector3(0, 0.25f);
         eggPosition[3] = new Vector3(0, -0.5f);
         eggPosition[4] = new Vector3(0, -1.25f);
         eggPosition[5] = new Vector3(0, -2f); 
     }
 
     //startup egg spawn
     void Start()
     {
         for(int x =1; x <6; x++)
         {
 
             int arrayIdx = Random.Range(0, eggSprites.Length);
             Sprite eggSprite = eggSprites[arrayIdx];
             string EggName = eggSprite.name;
 
             GameObject newEgg = GameObject.Instantiate(eggsPrefab, eggPosition[x], Quaternion.identity) as GameObject;
 
             newEgg.name = EggName;
             newEgg.GetComponent<EggPrefab>().EggName = EggName;
             newEgg.GetComponent<SpriteRenderer>().sprite = eggSprite;
         }
     }
 
 
     void Update()
     {
         MakeRandomEgg();
     }
 
     //spawn egg per click
     public void MakeRandomEgg()
     {
         if (Input.GetKeyDown(KeyCode.A) || Input.GetKeyDown(KeyCode.D))
         {
             int arrayIdx = Random.Range(0, eggSprites.Length);
             Sprite eggSprite = eggSprites[arrayIdx];
             string EggName = eggSprite.name;
 
             GameObject newEgg = GameObject.Instantiate(eggsPrefab, eggPosition[1],Quaternion.identity) as GameObject;
 
             newEgg.name = EggName;
             newEgg.GetComponent<EggPrefab>().EggName = EggName;
             newEgg.GetComponent<SpriteRenderer>().sprite = eggSprite;
         }
     }
 
     //move egg
     public void moveEgg()
     {
         if (Input.GetKeyDown(KeyCode.Z))
         {
             eggsPrefab.transform.position = positionLeft.transform.position;
         }
     }
 }