Hi @KWJ77,
Allow me to provide you an insight into the difference between Simple Start and Essentials.
The reconciliation feature is available for all versions of QuickBooks Online (QBO). The main differences between the Simple Start and Essentials are the option to create a bill and multi-currency support. You can view the Plans and Pricing page to find out what features are available for each version.
Should you start reconciling and is unsure how to reconcile accounts, view the article provided. It walks you through the whole process. From the set up all the way to the reconciliation bit.
Feel free to drop a comment below if you have any other questions. I'd be glad to answer them for you.