How do I join 2 tables and calculate 1 new column

I'm need to get 3 new columns with my SQL query. The first 2 columns only requires 1 table (Shipment_Info), but the 3rd column requires the 2nd table (Item_Info).

1. 1st new column = Shipment_Size (# of itemsID in that shipment)
2. 2nd new column = Shipment_ready (entire shipmentID is ready to be shipped. For an shipmentID to be ready to be shipped all the ItemIDs must be in a "Packed" status)
3. 3rd new column = Item_Stored (was this item stored atleast 1 time). If it was stored atleast 1 time value should be yes and if the item was never stored atleast 1 time the value should be no.

Shipment_Info_table:

Shipment_Info has three columns ShipmentID and ItemID and Item_Status. ItemID values are always unique, but ShipmentIDs will repeat because different Items can be in the same shipment, and item status can be in different states (Allocated, Filled and Packed).

Item_Info table:
Item_Info has two columns. ItemID, Operation, Op_time. ItemIDs will repeat because this table shows the different operations that have occurred to this itemID and the associated times.

DB Table: Shipment_INFO

DB Table: Item_Info

Ideal Output:

The code below gets me the first two columns, but I'm having trouble on how to join 2nd table and get the 3 column. Any help would be greatly appreciated.

 select ShipmentID,ItemID,
           count(ItemID) over (partition by ShipmentID) Shipment_Size,
          case when 
      sum(case when Item_status='Packed' then 1 else 0 end) OVER (partition by ShipmentID ) =count(ItemID) over (partition by ShipmentID)
                   then 'Yes' else 'no' end as Shipment_Ready
      from Shipment_INFO
    group by ShipmentID,Item_status,ItemID

I think you just want a simple case expression using exists:

select ShipmentID, ItemID
    , count(ItemID) over (partition by ShipmentID) Shipment_Size
    , case when
        sum(case when Item_status='Packed' then 1 else 0 end) over (partition by ShipmentID ) = count(ItemID) over (partition by ShipmentID)
        then 'Yes' else 'No' end as Shipment_Ready
    , case when exists (select 1 from Item_Info ii where ii.ItemId = si.ItemId and ii.Item_Status = 'Stored') then 'Yes' else 'No' end as Item_Stored
from Shipment_INFO si
group by ShipmentID, Item_status, ItemID;