Need help with php

[mudsnake]

Can anyone give me a good idea on how to install a php script. Heres were I am at
Edit file: config.php and change the values to match your server
$DBhost = "localhost"; // Host name
$DBuser = ""; // Database user name
$DBpass = ""; // Database password
$DBname = ""; // Database name
What do I change these to?
The first one has me totaly ignorant and the next three I believe I know. To be honest I am not even sure if I have created a empty data base like it asked to do. If it helps I am using h2o hosting with C-Panel.
I am new to any type or programming and trying to learn on my own, so if you can explain it as simple as possible that would be great.
Thanks in advance