FTPing a new website to hosting server.

I'm sure you'll have fixed this by now, though if not it looks like you may have to find whatever folder at the ftp site is configured to be the folder the web address points to. Very likely, this could be their httpsdocs folder: you could try putting a file in that folder and then use the filename straight after the web url to see if that's right. Wherever the web folder is, once you've found it you just put your new site in and that should be it.