To connect to filezilla you would use your domain name with no www. but with the .com (or .org, .net, .co.uk and etc) for the user name and the host name. The password is the same one you use to log in to your BT control panel (to access the file manager for example.)
Files would be uploaded into your public folder directly and the homepage should be named index.htm or index.html. You can change this, if you want a different file name for your homepage, by creating a text file named .htaccess and adding the line of text "DirectoryIndex filename.ext" replacing filename.ext with whatever filename you want your homepage to be.
You can copy a page you have elsewhere, like on your free webhosting account, by downloading it to your computer and reuploading it to your public folder on our side.
