Thank you for your question nolanatnameless!
You can copy your files and your database to a subdomain and make a duplicate of your site. I'm not sure what kind of site you have but the instructions for WordPress and Drupal at the following links.
308: Making a duplicate Drupal test siteMaking a duplicate WordPress site for testing
Moving other websites are the same steps as the WordPress and Drupal instructions. If you are developing on DreamWeaver or another local code editor, you can upload the site to a test subdomain to see how it works before uploading to your domain. The following is a tutorial on how to create a subdomain.
How do I create a subdomain in my control panel (cpanel)?
Hope this helps!
Best Regards,
James R