Thank you for bringing your question to the Community forum. Unfortunately, once you choose a template, there isn't a way to transfer that to another template. If you click on the Create button on the Campaigns page, that will take you to the template picker, where you can start out on a fresh template. I'm sorry for the inconvenience.
If you would like, I can also send you some information on our Professional Design services. With our design services, you can save time by letting us create a re-usable template to your specifications.