I appreciate you for visiting the Community regarding your stock concern, @bds2013cdm.
QuickBooks Online uses a perpetual inventory system. It means that the information on inventory quantity and availability is updated continuously as a function of doing business. That said, you do not have opening and closing stock entries if you are using inventory items.
However, to get the opening value of your inventories for the year, you can pull up a Balance Sheet report and enter 01/01 as the starting date and use 12/31 as the closing date to get the ending stocks.
I'll walk you through on how to achieve this:
Click on Reports from the left pane.
Look for Balance Sheet from the search box.
Enter 01/01 as the starting date of the Report period and select 31/12 as the ending date. The year may vary of the data that you want to pull up.