Renaming the admin folder

Hello everyone/anyone? I'm a new startup using the Zen Cart application. I'm using v1.3.9c. In regard to **RENAMING **the **admin **folder and editing the configure.php files... which file should I edit? I found two instances of the configure.php file in the "public_html" folder and the "www" folder both under subfolder location "shop/admin/includes". What's the difference between the two folders? and again which one should I edit?

Two more questions, both state within the file that they are different from the "store" version? What does that mean? Also, why do the files have to be downloaded using an FTP program when the hosting server site allows the file to be edited there?

Soonest response much appreciated.

which file should I edit? I found two instances of the configure.php file in the "public_html" folder and the "www" folder both under subfolder location "shop/admin/includes". What's the difference between the two folders? and again which one should I edit?
public_html and www are the same folder content - So this is not actually two instances

There are two instances and they are as follows
/includes/configure.php
/your_new_admin_name/includes/configure.php

both state within the file that they are different from the "store" version? What does that mean?
See above as to "both" and as to store version

Also, why do the files have to be downloaded using an FTP program when the hosting server site allows the file to be edited there?
Those editors are not reliable - use at your own risk
You really should use a good plain text or code editor for php files
Such as these free to use ones
notepad++
crimson editor