I would say that your database connection will likely be the issue... also...
mysql_query($sql) is missing a parameter, your $link to your database that you get from your connection.
suggest that you post your database connection file but edid out the username and password details!
You did take a backup to upload to the new server?
As stated, mysqli over mysql functions
you also may have to look at your php.ini settings to ensure that php is operational and your able to execute PHP scripts.