Hi alldaymain,
I can think of two ways on how you can find all saved estimates in QuickBooks Online (QBO).
First is the Sales tab. See the steps on the screenshots.
You can also run a report to list all the estimates. Go to the Reports tab then search estimates.
When these estimates are approved by your clients, you are ready to convert them to invoices.
The Community is always here if you need anything else.