Setting up current WP with Multi-site

I am about to enable my ESTABLISHED WP website with multi-site using sub-domains I’m wondering if my current WP is installed as it needs to be on my server.

The following webpage confuses me: http://codex.wordpress.org/Before_You_Create_A_Network

On the one hand, it states under the section, “Domain Based”: “WordPress must run from the root of your webfolder (i.e. public_html) for subdomains to work correctly. They will not work from within a subdirectory.”

And then shortly after in the section, “Wordpress Setting Requirements” it states: “When you install a multisite network you start from an existing WordPress installation. If it is a fresh install with its own domain name, then you do not need to read this section.

If it is an ESTABLISHED site

, or not reachable using just a domain name, then the following requirements apply to allow it to be converted to a multisite network. Giving WordPress its own directory works with Multisite as of 3.5, however you must make the ‘own directory’ changes before you activate Multisite.”

Here is my current directory structure:
\public_html
\cgi-bin
\themes
\wp-admin
\wp-content
\wp-includes

My WP is installed to the root, RIGHT? Do I need to move my WordPress to its own directory before turning on multi-site? If I do have to move it, do I set up the wildcard sub-domain in cPanel and the wildcard DNS before or after the relocation?

And yes, my server is Apache — it uses .htaccess and mod_rewrite is active.