Let me share the difference between QuickBooks Online and QB Self-Employed, contact-vanago-c.
You'll want to use QB Online if you need to track accounts receivable and accounts payable. It is designed to track business accounts. It has advanced features, so it can track sales tax, keep track of inventory.
If you need to file a Schedule C document with Form 1040 during tax season, QuickBooks Self-Employed is the right one for you.
You can check this comparison chart, https://quickbooks.intuit.com/accountants/compchart/.
Let me know if you have more questions about QBSE. I'll be more than willing to answer them for you.