1. We recommend you install Quickbooks.
You can try Quickbooks Online's free trial.
Click on your version's Try It Free link.
Fill out the sign up form and press Sign Up.
It will load for a bit.
Fill out your company information and go through the prompts.
Press the plus sign at the top of the page.
Select Invoice to create an invoice.
This page allows you to create customers.
It also allows you to create products.
2. Sign up for inSitu Sales. You can click in Sign in with Intuit to create an account with the same email used in QuickBooks online
Click Sign in with intuit.
Your account is now created.
Close out of the welcome window, and press Connect to Quickbooks at the bottom of the page.
Click Authorize, and you are all set to go.