Hi there,
Thanks for reaching out to us here in the Community. QuickBooks Online makes it easy for you to record your sales. I'd be happy to explain how you can create sales transactions in QuickBooks Online.
Once you've finished saving the transaction you're currently working on, you can begin the process of recording your next sale. Depending on when you receive the payment, there are two ways to record a sales transaction in QuickBooks Online.
1. For a deferred payment, use Invoice and Receive Payment. Think of this as a two-part transaction. First, you create the invoice to record the sale. Later, when your customer pays, you record a payment against that invoice.
2. For an immediate payment, use a Sales Receipt.
For more information about invoice and sales receipts, as well as instructions on how to create them, take a look at this article: Should I use an invoice or a sales receipt?
I hope this helps to answer your question. If there's anything else I can do for you, let me know.
Have a great day!