Hello, coffeelady1.
Selecting an account in the account field will depend on how you want to post your records. Meaning it's up to you what income account you'll be using. However, you can't select the AR account. The AR account is for invoices.
To make sure your books are accurate, I'd recommend seeking help from a professional accountant in selecting an account. They can guide you with the specific type that fits your business.
For future reference, read through this article: Chart of accounts in QuickBooks. It helps you learn about the different account types available in the Chart of Accounts.
Hit the Reply button if you have other questions about QuickBooks. I'll do whatever it takes to ensure your concerns are addressed. Enjoy the rest of your day.