Ecommerce Site Duplication for makeover

I’m about to embark on a redesign of a current Ecomm Plus Site, but would prefer not to do the work on the live site until it is all approved by the client. What are the steps for a smooth transition?

Can I work on the CMS portions (store items) without affecting the current? Anything I should be aware of regarding the hosting? Can I publish a sample under webflow.io for review?

The shopping cart is not handled by Webflow, but uses js scripts that reach out to another shopping cart.

Thanks for any help you can provide.