1) You need to create your database using the cPanel database creation feature

2) You need to assign username/password and any necessary privileges through the cPanel database management interface

3) You need to add your computer IP from which you will connect using the cPanel Remote MySQL feature. If you are not sure what your IP is simply go to http://www.whatismyip.com - which will show your IP address

Then in your application/code you need to specify for hostname the same hostname as the servername specified in your account Welcome email or you can also use the IP address of the server (either way). The port to which you need to connect is 3306