Hello there, bbalentine15.
I'm joining this thread to help you choose the accounting plan that's right for your business.
Yes, Fiat Lux - ASIA is correct. QuickBooks Online Essentials is good enough to track your invoices. Still, I'd recommend visiting this article to compare the features in Simple Start, Essentials, and Plus plan: QuickBooks Accounting Plan Comparisons.
Once you get there, you'll see this page. You can click the collapsible arrow to view the description of each feature. This will help you decide what plan suits your needs.

Also, you can import your QuickBooks Desktop company file to QuickBooks Online. Let's use this article for further guidance: Move data from QuickBooks Desktop to QuickBooks Online.
Here are some articles that provides insights about handling income and sales transactions in the program:
Let me know if you have more concerns about managing invoices in QuickBooks. I'll be happy to assist you anytime. Have a good one!