You need to understand the difference between the SERVER path and the HTTP path.
The SERVER path will typically comprise a sequence such as:
home/jimmysmith/public_html/
Where the public_html is the ROOT directory into which all files will reside.
Some servers have different NAMES for the root:-
httpdocs, for example
All your zencart folders/files need to go into the ROOT directory, not before it.
The HTTP path will know (from the way the server is configured), that it must look inside the ROOT (public_html) for further "information" regarding the locality of the index file which must then kick the site into life.
If you want your zencart installation to run directly from the ROOT directory, then all the files get loaded into that directory.
If you want your site to run in a SUB-DIRECTORY (or possibly as a sub-domain), then you load the files into a named SUB-DIRECTORY which itself sits inside public_html.
So... just where you LOAD the initial folders/files will depend on whether you want the site to run as the main site:
A: http://www.myzencartwebsite.com/
or in a sub-directory:
B: http://www.myzencartwebsite.com/webshop/
If you want A, then ZC gets ftp'd to go inside "public_html" or "httpdocs" , or whatever your server root directory is called.
If you want B, then ZC gets ftp'd to go inside "public_html/webshop/"
Then, when you run the install via a browser, you navigate to:
A: http://www.myzencartwebsite.com/zc_install
or
B: http://www.myzencartwebsite.com/webshop/zc_install
