File Location

Hello,
I am very new at using wordpress and designing my own website based off of this program. I’ve found it could be a great tool and had a question to start things off. After downloading the program and installing it for a couple of website I have had no problem. All the files reside in the original wordpress folder and now exist on the server as such. I see all of these website in the showcase and was wondering how do I get my home page to be the index.php file that is in the wordpress folder? Do I need to move everything out of the wordpress folder and into the public_html directory? or am I suppose to re-write the code for the index.php. When I do try to move or copy the index.php file out of the wordpress folder and into the main directory I get the following error: Fatal error: Call to undefined function get_sidebar() in /home/footzone/public_html/wordpress/redmond.php on line 108
Any help or point in the right direction would be greatly appreciated.