Good day to you, @abovebeyondplumb.
I’m more than happy to guide you on where you can search your customer by their address.
You can go to the magnifying glass icon and type in the address of your customer. I’ve added a screenshot below for your visual reference. 
I’ve also added this resource that you can use for future reference in managing your customer lists in QuickBooks Online (QBO): Add and manage customers in QuickBooks Online.
If you have any other concerns or questions about managing your customers or invoices, let me know in your reply. I’ll be around ready to lend a hand. Keep safe and take care.