New User Upgraded now can not edit

I am still new to this. I am hosted by AQHost and installed Zen Cart using to cpanel on their site. Things start out ok, then I upgraded to 1.3.7 and now I am unable to access any pages to edit. When I go to Tools>definepages editor> (any page) I get the following mesage:

Error: I can not write to this file. Please set the right user permissions on: /home/storename/public_html/includes/languages/english/html_includes/classic/define_main_page.php
**Note: you should always edit the files located in your current template override directory, Example: /languages/english/html_includes/
Be sure to make backups after changing your files.

Editing file:
/home/storename/public_html/includes/languages/english/html_includes/classic/define_main_page.php
**
I have no clue where to find these files. I made sure I had permissions set correctly through cpanel but it did not help.
Any help is appreciated.

I removed the real name and replaced it with 'storename' in info above.

Ray

You should be using your own templates and overrides directory ...

You need in this case:
/includes/languages/english/html_includes/classic

To have files set to 777

Linda;
Thanks for the quick reply. Unfortunatly, I am so new at this I have no idea where to find those files. Where do I go to access them. Anything I need to do to edit them?
Ray

If you read the error message it is pointing to the exact location where you should find these in your FTP program ...
/home/storename/public_html/includes/languages/english/html_includes/classic