problems with GetComponent,Problems with GetComponent

Hello Recently I started messing with Unity and I've been learning through tutorials. I started a project of a simple game of the type of survival and I was taking inventory and I came across a mistake, which I can not solve. Assets/Scripts/Inventario/ItemData.cs(18,69): error CS1061: Type UnityEngine.GameObject[]' does not contain a definition for GetComponent' and no extension method GetComponent' of type UnityEngine.GameObject[]' could be found. Are you missing an assembly reference?

the problem is GetComponent. Someone can help me?

    using System;
     using System.Collections;
     using System.Collections.Generic;
     using UnityEngine;
     using UnityEngine.EventSystems;
     
     public class ItemData : MonoBehaviour, IBeginDragHandler, IDragHandler,IEndDragHandler {
     
     
         Inventory inv;
     
         public Item item;
         public int amount;
         public int curSlot;
     
         // Use this for initialization
         void Start () {
             inv = GameObject.FindGameObjectsWithTag("InventoryManager").GetComponent<Inventory>();
             this.transform.position = inv.slots[curSlot].transform.position;
         }    
     
         public void OnBeginDrag(PointerEventData eventData)
         {
             if(item.ID != 1)
             {
                 this.transform.SetParent(this.transform.parent.parent.parent);
                 this.transform.position = eventData.position;
             }
         }
     
         public void OnDrag(PointerEventData eventData)
         {
             if (item.ID != 1)
             {
                 this.transform.position = eventData.position;
             }
         }
     
         public void OnEndDrag(PointerEventData eventData)
         {
             this.transform.SetParent(inv.slots[curSlot].transform);
             this.transform.position = inv.slots[curSlot].transform.position;
         }
     }