As a newbie, I found this response confusing:

"Look at estimates, you can edit a template and rename it  customer PO if you like, progress invoice from the estimate."

With the benefit of a little more experience with QBO, it now makes sense. I think I would have punctuated it differently:

"Look at Estimates. You can edit a template and rename it 'Customer PO' if you like. You can then create a progress invoice from an estimate based on the new template."