run a ee project on localhost on different machine without passing account information.

I am new to ee. I just got a ee project which is developed by someone else. They gave a file structure and as they have a already bought ee and its licensed. Now I want to run that project on my linux machine using apache2 server. I made changes in system/config/database.php and system/config/config.php also cloned database in phpmyadmin . but when I try to access admin or index it keep giving me server error. Note: my server is compatible and configured correctly to run ee project. I have tried ee_server_wizard an even running core, Both worked fine . so I’m missing something in that project config but can’t figure what it is.