Undo the changes you made or restore a backup and try again. The best way to learn is to make mistakes and figure them out yourself.
As said before this really is not the place to discuss problems with creating a server. For apache help try here:
http://httpd.apache.org/docs-2.0/If you are *really* struggling to install a server I recommend xampp. It's what I used for my test server and it configures mysql, php, apache all at once and is available for free from here:
http://www.apachefriends.org/xampp-en.htmlIt's very easy to install and setup and only takes a few minutes
Please do not start any more topics here not directly relating to YABB SE as they will end up deleted.