..but it’s worth it, I promise :).
Go to https://www.appsheet.com/HowItWorks/DataSource/google-drive (Links to an external site.)
Follow the guides on how to get started with AppSheet, and create a simple prototype app with Google Sheets as the data source.
At minimum, you must have three tables (and also three views to go with each):Customers
Sales
Payments
(and more if you want…)