I need a Supply of Service contract written

I am looking for someone to write a simple Supply of Services Agreement covering my dog training services that I provide.

The contract would need to be able to be used for multiple businesses so an option to add information like name of business and details of the services and payment terms would be great. For example, if they sign up, they have to commit to x amount of sessions at a y rate (x and y will be some of the things I will need to add in as this can change)

Thanks