Can I copy an existing estimate to make a new estimate?

Welcome to the Community, Bud.

Yes, you can copy an existing estimate to make a new one. I've got steps on how to copy an estimate.

Here's how: 

1. Go to Sales, then select Estimates.
2. Find the estimate you want to make a copy of.
3. Under the Action column, click the drop-down arrow.
4. Tap Duplicate, then enter all the necessary information.
5. Tick Save.

I'll add this article for you to have additional information on how to set up estimates in QuickBooks Online: Create and send estimates in QuickBooks Online

Additionally, you can check on this article to learn how to personalize and add specific info to your sales forms: Customize invoices, estimates, and sales receipts in QuickBooks Online

Don't hesitate to hit the Reply button if you have further concerns in creating an estimate or any QuickBooks-related concerns. I'm always here to lend a hand. Take care.