Hello there, @userjmmasonry13.
When you send estimates to your customers in QuickBooks Online (QBO), the professional form with business letterhead is included through a downloadable file. To do this, you'll have to make sure you attach a PDF file when sending online forms from the Account and Settings page. Let me guide you how.
- Go to the Gear icon.
- Select Account and settings.
- Go to the Sales menu.
- Click anywhere in the Online delivery section to open its details.
- Select the PDF Attached box.
- Click Save.
I've attached a screenshot below that shows the last four steps.

You're able to monitor all your estimate transactions in QBO by pulling the Estimates by Customer report. This way, you can identify whether an estimate is already accepted and/or invoiced. Just go to the Sales and customer section from the Reports menu's Standard tab.
Also, you can create attractive and professional-looking estimates and other sales forms in QBO. With this, you're able to add info that matters most to your business. For the step-by-step guide, you can check out this article: Customize invoices, estimates, and sales receipts in QuickBooks Online.
I'm just around to help if you have other concerns about sending estimates and other sales transactions in QBO. Take care always.