Can I find my mysql details only in my ftp or is there a way to find it in coppermine gallery itself. So that i don't have to log in in my ftp?
You used that data when installing Coppermine so you should know this.
When installing pnCPG, this info is only relevant when Postnuke and Coppermine are on different servers and/or have different Database users.
Normally this is not the case.
Cas
To edit the mySQL settings for Coppermine, edit your_coppermine_folder/include/config.inc.php