How to handle a data processing agreement?

I have a customer asking for a data processing agreement. My application is hosted on servers within the US. I'm not making enough money currently to hire a law firm to take care of this.

I found this template: https://gdpr.eu/data-processing-agreement/

It seems pretty simple, but I want it looked over and tweaked to fit my particular situation without spending thousands of dollars. My main concern is Section 11 about Data Transfer.

Does anyone know a good way to get this taken care of without spending a ton of money?