Help! I built the site on the wrong theme

Good evening everyone,

My boss asked me to build a website using the Variations Theme by following Tyler Moore on YouTube.

I was going along really well until I was notified that we needed to change direction and make it a sales page with the ability to take payments. Hence, we also need a shopping cart.

I did go to use a new theme but it took all the content I had in the Variations theme and automatically transferred it, which is not what I wanted. I would just like to save that content somewhere separately if possible

Is there a way to preserve the work I've done, in case there are further changes, and start fresh with a new, clean theme?