Copy site to a new wp, so i can make changes on non-public

I'm trying to copy this site onto a new wp site, so that i can try out different themes and configurations in a nonpublic space. I have another wp page set up and just want to copy the current site to the new one so i can play around with it. Thanks!
i'm not a developer, but my board wanted me to make changes to the site - i'm learning as i go. thank you!!