The new host is Siteground. My friend got involved and said the uploaded files needed changing to html.
Files need to be uploaded to public_html folder. Tried and tried. Used FileZilla to upload to ensure files went into correct folder. Nothing. No site showing.
I have never had any problems like this. Always uploaded to various hosts and away I went.
But you have now transferred to a new host! That host is responsible for propagating your site.
However, I agree there is something seriously wrong with how that site displays!
I'm attaching below screenshots of part of the Filezilla workscreen for my own web site. The first one, the RHS of the workscreen shows the remote server window. My site has to be uploaded to "htdocs" (highlighted), yours should show "public.html".
When I click on that htdocs folder to open it I see this (clearly only a small part of mine is shown here):
Those are my actual website files.
I think yours should appear very similar.
If you would like to show a screenshot of your FZ workscreen please feel free to do so but please ensure ANY confidential data, like server name or password etc., are fully obscured!
Jeff
EDIT; to add, I have just reopened your son's website and everything now seems perfectly fine!..Clearly, I cannot be certain that the whole site is displaying properly but it certainly seems to be! If so, it would appear your host has now properly propagated the site.