Hi there Diane18,
It's important that all your transactions are entered correctly for your books to be well balanced QuickBooks Desktop is a great tool able to help keep track of invoices, payments, and credits so you know the amount owed by your customer. I can point you in the right direction for assistance with entering this sale financed.
To know how you should be entering this sale to make sure it's correctly represented in your books, I recommend speaking with your accountant. Their expertise will be able to tell you if you should be creating one single invoice that includes all the information, and then applying monthly payments to it, or if there should be individual invoices for each payment. They'll also be able to assist in choosing the right line item for each transaction so that your books are affected in the right way. You can find an accountant near you who has experience using QuickBooks software by checking out our Find an Accountant page.
If you have any other questions, feel free to reach out here.
