But let me clarify a few things first, are paying a bank with US dollar or receiving a payment from US dollar transaction? Please know that you can only assign a currency to your customers or vendors.
You can read this article to learn more about how multicurrency works: How Multicurrency works.
I've got you this helpful article in case you need some ideas about managing your account: Reports and Accounting.
Please touch base with me here for all of your QuickBooks needs, I'm always happy to help. Thanks for dropping by.