While doing stock update, the warehouse decides in which shelf locations your goods are stocked. The sizes and price vary in different warehouses.
Storage places will be filled to the fullest and emptied shelf by shelf. Empty shelves are not charged, you only pay for used storage places. Price lists are found on the myOGO front page.
If there are any goods that have expiration dates, you can tell the warehouse staff to put the old goods at the front of the shelf and new ones at the back. You can leave a comment for the warehouse when you are making the stock update.
Currently for the TLL-warehouse you can see the shelf names/codes and stock types at the Stock locations page.