This means the domain name is OK, the hosting is OK, but there is something wrong with the page.
The home page of a website is normally index.html, index.htm, index.php on Linux servers, or index.asp, default.asp, on Windows servers. e.g. a file name “home.htm” is not a valid home page.
If a valid home page does exist, check it for coding errors, e.g. is it coded to include a header file that does not exist.