Welcome to the Community forum, @waiheng_lau.
QuickBooks right now is a perpetual inventory, in which there is no opening and closing stock. The Profit and Loss report will only show the transactions recorded within the date range.
You can get the beginning and ending value for the period from the balance sheet.
To know more about running reports in QuickBooks, you can consider checking this article: Run reports.
You can get back to me if you have any other questions, I'm here to answer it for you. Have a great day!
