Calibre was meant to run on your PC, not on a remote website (unless, of course, you have a dedicated server and can run all sort of apps on it). Calibre has a built-in http server for serving online catalogs.
For shared hosting, if you want something you can upload to your website, check out
Calibre2Web (currently Windows only) by itimpi. Instructions are in the zip file. You just upload the generated XML files along with a copy of your Calibre library to your webhost. It even presents you with a hierarchical/categorical view of your library ala-Stanza which is something currently missing from the built-in Calibre server.
Just remembered, ChrisZA made a very clear, easy to follow guide over here:
https://www.mobileread.com/forums/showthread.php?t=42023