If you haven’t downloaded an FTP (File Transfer Protocol) Program, please do so and download Filezilla.
The home directory differs host by host, but it is usally the “publichtml” one. This is the place to put index.html to.
Make sure you do NOT put the file into one of the folders you see there – put it UNDER those folders. Also put all your pictures and other files for you site in this same directory or if you are sure you know how to reference them in html, you may place them in an images folder.