Hi there, @The_Token_Shop.
The cost of goods sold (COGS) in inventory is usually only affected when you sell inventory items through invoices or sales receipts. When you sell an inventory item, you can generate the Transaction Journal Report for the corresponding invoice or sales receipt. This report will show the transactions for Sales/Accounts Receivable and Inventory/COGS. These transactions will credit the Inventory Asset account and debit the COGS accounts.
I'm adding these articles that will help you track your items:
I'd be glad to help if you need further assistance with running your financial reports. Have a great day.