As a developer my perspective on staging a wordpress site is that it’s not an easy task, even for developers.
Here’s a good site for wp questions: https://wordpress.stackexchange.com/search?q=staging
I recently setup a staged wordpress site using a subdomain, git for versioning, and mysqldump for cloning the database. However it wouldn’t be useful for me to list the linux commands that I used to accomplish this as they are specific to my hosting environment.
Maybe your best bet is to start a new one?