It looks like you’ve put your theme in the wrong place & its overwritten the WordPress index.php.
You need to delete the themes files you put in the root of your site, put a new copy of the original index.php back there to replace the one which was overwritten & then upload the red-delicious theme folder to the correct location, ie in the wp-content/themes folder.
The index.php in your site root (the same level as your wp-config) should look like this:
<?php
/**
* Front to the WordPress application. This file doesn't do anything, but loads
* wp-blog-header.php which does and tells WordPress to load the theme.
*
* @package WordPress
*/
/**
* Tells WordPress to load the WordPress theme and output it.
*
* @var bool
*/
define('WP_USE_THEMES', true);
/** Loads the WordPress Environment and Template */
require('./wp-blog-header.php');
?>
