re:Anyone here good with database and joomla possibly?
My first suggestion would be double check your connection string information. IE database, username, password
Make sure the connection information is still accessible by the site or at least the file holding the connection information is still accessible.
I don't recall the exact PHP syntax but your connection file may not be able to access the database and it's trying to load the offline.php file, which may not exist, to give the user a "friend" error message.
I'll try to keep an eye on the boards if you have any more questions.