Getting a copy of my pre-existing site as a database

I downloaded Wampserver, wordpress, and got a database up and running. Thing is I already have a site and I want to modify that, not a new site.

I’ve been trying to find tutorials about how to do this, but I am having trouble finding one that doesn’t assume I’ve done some form of WordPress based work before. It’s frustrating.

So how do I copy my current site to wampserver/phpMyAdmin as a database?