enchesss
If you want to install Joomla to a second ibay, then do it the same way you already installed Joomla to the first ibay. To my knowledge there is no rpm available for installing to an ibay, so you need to follow installation notes on the Joomla website ie unpack the tar.gz file & manually configure the configuration files and database etc.
Given your level of unsure knowledge, I think you would be better off removing the installations you have and starting again.
Do the first install to /opt/joomla using the Joomla contrib here
http://wiki.contribs.org/JoomlaThen follow the additional steps in this howto to point your virtualdomain at the /opt/joomla location
http://wiki.contribs.org/Web_Application_Redirect_TutorialThe above should work reasonably smoothly if you follow instructions carefully and completely.
Only, and only when, you have the first site fully functional as you want it to be, then install a second copy of Joomla. If you install again using the contrib rpm, then you will probably overwrite the first installation (which you do not want to do), so in the second case you need to follow some manual steps outlined in this Howto.
You could copy the files from /opt/joomla to /opt/joomla2, but make sure that permissions stay the same.
The best way to achieve this is to pack the /opt/joomla folder as a tar.gz file and then unpack it to /opt/jooml2 or similar procedure that does not change permissions and ownership of files etc.
Then to configure other aspects eg templates and mysql database etc, follow the steps in
http://wiki.contribs.org/SME_Site_MakerIf you want to point another virtual domain at the second Joomla install in /opt/joomla2, then you will need to follow the additional steps in this howto to point your virtualdomain at the /opt/joomla2 location
http://wiki.contribs.org/Web_Application_Redirect_TutorialIf you cannot undertstand how to do the above then you should not really be trying to do these things on a sme server and you should be paying someone else to do it for you.
You have access to all the information needed to achieve this task, and it's not really that difficult an issue.