Backup Site

Sorry for all the questions just wondering how to setup a backup site?

For example I usually have a backup site like test.maindomain.com.  This site is turned off and setup with a test database.  I do this to test plugins or version upgrades before I go "live".  I didn't see a config file in inc.  Can you tell me what I can do if I create a test db and import that and copy the files over.  Do I need to redo the install or can I just edit a file somewhere?

just upload dolphin to your subfolder and install  if you have already installed you can edit inc/header.inc.php

You can copy your current site and database.  Upload the files to the new directory and edit the /include/header_inc.php file so that it points to the correct places.  Create a new database and import the database from the current site.  Create a subdomain or domain to use for the test site.