If you have uploaded your website files this will be a php script or database error. Please try the following:
1)create a file with notepad called : .htaccess
And place inside this file the line : php_value display_errors on
Then upload this file into the folder of your script. This will enable Display errors on your domain and your browser should see the php / database error causing the problem, so that you may correct the error.
Please ensure that the .htaccess file is chmod 644
Note: If you already have a file named .htaccess there, simply add the above line to that file rather than replacing it.