Thanks, I can make the form but how do I convert it into a downloadable

Thanks, I can make the form but how do I convert it into a downloadable PDF for the customer?

If you already have an online form, please see this guide to create a PDF Form: How-to-create-a-pdf-form

If your main goal is just to create a fillable PDF, then please see this page:

https://www.jotform.com/fillable-pdf-form-creator