I am truely a noob...where do i find phpmyadmin to manage password for coppermine etc..
phpMyAdmin is not a password manager tool, but a tool to directly manipulate the database. Definitely not recommended for complete newbies to directly mess with the database! To manage your users, you don't need phpMyAdmin. Only use it to recover your lost admin password if no other method works for you.
To find phpMyAdmin, you could just have googled (http://www.google.com/search?q=phpmyadmin) for that term. It would have led you to the phpMyAdmin homepage (http://www.phpmyadmin.net/).