Do I get a tracking number for invoices I send out
You won't get a tracking number for your sent invoices through the program, @Deepain. However, you can track their statuses, such as Open (Sent) or Open (Viewed). I'll guide you how.
Go to Sales from the left menu.
Select the Customers tab.
Choose a customer.
In the Transaction List, locate the invoices you send out.
Review the status of each transaction in the Status column.
The screenshot below shows you the last two steps. To learn more about the description of an invoice's status, see the How will I know if already sent an invoice? section through this article: Send Invoices.
I can see how beneficial it is to get a tracking number for all your sent invoices. Rest assured that I'll take note of your suggestion and submit this to our product engineers. They can find a way to add this functionality to QuickBooks Online (QBO) for future releases. I recommend visiting this website: QBO Blog. This link provides you more details about our product improvements.
Once your customer pays an invoice, the system will automatically change its status to Paid in the Status column.
Aside from sending invoices, you can send other sales transactions, such as sales receipts. Just go back to the Transaction List of your customer. Then, click Send from the Action column. You can also perform other tasks, such as viewing, editing, printing, voiding, or deleting them. View the screenshot below for your visual reference.
You can post anytime if you need more guidance. Have a great rest of your day, @Deepain.