There are some ways on how you can record the paid transactions,
For recording a deferred payment, you can create an invoice to record the
sale. Then record the payment against that
You can also create sales receipt to record an immediate payment. Just follow the To create a Sales Receipt section in the Should I use an Invoice or a
Sales Receipt? article.
If the paid transaction is a credit card payments, you can check out this article on how to record them: https://community.intuit.com/articles/1777536.
To learn more about managing money in and money out in QBO, you can check out the articles in this link: https://community.intuit.com/browse/quickbooks-online-intl-moneyin-moneyout.
I'm confident the steps I've provided helps you record the paid transaction. Just reply to this post if you need anything else with recording payments in your account. I'd be glad to help.