Save and load inventory

I really dont know where to start, i really dont have any idea on how to save my inventory, I would really appreciate if someone just give me a hint or a bit knowledge on saving this inventory.

 public class Inventory : MonoBehaviour {
 
     public List<GameObject> Slots = new List<GameObject>();
     public List<Item> Items = new List<Item>();
     public GameObject slots;
     ItemsDatabase database;
   
     public GameObject tooltip;
     public GameObject draggedItemGameObject;
     public Item draggedItem;
     public int indexOfDraggedItem;
     
     public bool draggingItem = false;
     
   
 
     void Update()
     {
        if(draggingItem)
         {
             Vector3 posi = (Input.mousePosition - GameObject.FindGameObjectWithTag("Canvas").GetComponent<RectTransform>().localPosition);
             draggedItemGameObject.GetComponent<RectTransform>().localPosition = posi;
             
         } 
     }
 
     public void showTooltip(Vector3 toolPosition, Item item)
     {
        tooltip.SetActive(true);
         tooltip.transform.GetChild(0).GetComponent<Text>().text = item.ItemName;
        
         tooltip.transform.GetChild(2).GetComponent<Text>().text = item.ItemDesc;
     }
     public void closeTooltip()
     {
         tooltip.SetActive(false);
     }
 
     public void showDraggedItem(Item item, int slotNumber)
     {
 
             
             indexOfDraggedItem = slotNumber;
             closeTooltip();
             draggedItemGameObject.SetActive(true);
             draggedItem = item;
             draggingItem = true;
             draggedItemGameObject.GetComponent<Image>().sprite = item.ItemIcon;
 
             
         
     }
 
     public void closeDraggedItem()
     {
         draggingItem = false;
         draggedItemGameObject.SetActive(false);
     }
 
     int x = -60;
     int y = 101;
 
     void Start () {
      
         int SlotAmount = 0;
         database = GameObject.FindGameObjectWithTag("ItemDatabase").GetComponent<ItemsDatabase>();
 
         for (int i = 1; i < 5; i++)
         {
             for(int k = 1; k < 4; k++)
             {
                 GameObject slot = (GameObject)Instantiate(slots);
                 slot.GetComponent<SlotScript>().slotNumber = SlotAmount;
                 Slots.Add(slot);
                 Items.Add(new Item());
                 slot.transform.SetParent(this.gameObject.transform);
                 slot.name = "Slot" + i + "." + k;
                 slot.GetComponent<RectTransform>().localPosition = new Vector3(x, y, 0);
                 x = x + 60;
                 if(k == 3)
                 {
                     x = -60;
                     y = y - 50;
                 }
                 SlotAmount++;
             }
         }
 
         //additems to the slot, can be stacked(consumable)
         addItem(4);
         addItem(4);
         addItem(10);
 
 
         //addItem(11);
 
 
 
 
     }
 
     //stacking items in slot
     public void checkIfItemExist(int itemID, Item item) 
     {
         for (int i = 0; i < Items.Count; i++)
         {
             if (Items[i].ItemID == itemID)
             {
                 Items[i].ItemValue = Items[i].ItemValue + item.ItemValue;
                 
                 break;
             }
             else if (i == Items.Count - 1)
             {
                 addItemAtEmptySlot(item);
                 
             }
         }
     }
 
     public void addExistingItem(Item item)
     {
        
         if (item.itemType == Item.ItemType.Consumable)
         {
             checkIfItemExist(item.ItemID, item);
         }
 
         else
         {
             addItemAtEmptySlot(item);
         }
 
       
 
     }
 
 
 
     void addItem(int id)
     {
         
         for (int i = 0; i < database.items.Count; i++)
         {
             
             if (database.items[i].ItemID == id)
             {
 
                 //another if for "MATERIALS"
                 Item item = database.items[i];
                 if (database.items[i].itemType == Item.ItemType.Consumable)
                 {
                     checkIfItemExist(id, item);
                     break;
                 }
                 else
                 {
                     addItemAtEmptySlot(item);
                 }
                 
 
             }
         }
     }
 
     void addItemAtEmptySlot(Item item)
     {
     
         for(int i = 0; i<Items.Count; i++)
         {
             if(Items[i].ItemName == null)
             {
                 Items[i] = item;
                 break;
             }
         }
     }