Sheet setup

Hi All

I am trying to figure out how to set up my data so I can achieve this in an app.
I have a list of clients. I have 3 products. I need to see a forecast of orders vs actual orders per client, per product per month. How would I set this up?


Thank you Steve but I am familiar with building apps. With this one I have a problem with forecasting sales for 3 products per month. Not sure how to achieve this without having multiple rows for each client. So if I forecast that client 1 will order 2 units of product 1 per month, 3 units of product 2 and 5 units of product 3. Would I have to enter Data in 3 different rows to be able to then match by product to actual sales?