changing the front page in drupal 6.6

In drypal you don't actually change... You create content. Content is diferent types. Then you PUBLISH content.
Any content you add (say a story type) is going in your front page if you choose to do so. Think that drupal displays content in front page like a blog does.
If you want to display complex content in front page you have to use some modules (maybe panels, views, and cck ...).
Drupal has a steep learning curve. Play with the simple basic options to start and proceed later for more complex home page layouts.
It is difficult to make you understand, for example the views and cck modules operation for know. This should confuse you more.
But you have to know that with drupal you can do just EVERTHING you can imagine !

start here: http://drupal.org/getting-started/6

ReliabilityConsistencyFeedback ------ NeverAchivable -------

Create the node you want as front page, copy the path (for instance "node/7"), go to /admin/settings/site-information, enter the path in the 'Default front page' field and save the configuration.

By the way, you are expected to search the site first before you ask questions on the forum. If you search drupal.org for "front page" the first result is this excellent piece of documentation: http://drupal.org/node/265172.