Hello there, @bianca.
Thanks for visiting the Community. Yes, you can add and connect as many bank and credit card accounts as long as it's supported by QuickBooks.
Simply follow the same steps you've used to set up your online banking. In case you can't find your bank, follow the step-by-step guide in this help article: Find your bank account when you connect to online banking.
Feel free to visit again if you have additional questions. We're always here to assist you more.