To use MySQL in your website you will first need to create a MySQL database and a MySQL User. You can do this from cPanel. (Don't forget to link the User to your Database).
Then you need to configure your script to connect to MySQL, the following settings should be used:
• Host/Server Name = 'localhost'
• Port = '3306'
• Username = [Your*cPanel username followed by an underscore and the MySQL username you configured in cPanel]
• Password = [The password that you used when creating the MySQL user]
• Database = [ Your cPanel username followed by an underscore and the name of the database that you created in cPanel]
Free hosting accounts do not have remote MySQL access.