Getting error message upon installation
I don't know why all that HTML markup was displaying for you--that's a bit of a bug.  However, the real error message is in there: CiviCRM 4.6.10 requires MySQL trigger privileges.

The MySQL user that CiviCRM and Joomla use for connecting to the database needs to have the ability to create triggers.  You or whoever maintains your server will need to grant that permission to your database user before you proceed.