When you have a website with files in a directory,
you can specify which file to pick ... like "index-1.htm"
If you don't specify a file, it will pick the default, which is "index.html".
If more than one "index" file exists with different extensions, there is a priority
in which the default is picked.
There can be 3 different namings for index:
This URL seems to be your real URL:
In your main directory, make sure "index.htm" exists and there is no other "index.html" or "index.php" file.
The other issue is within a file called ".htaccess" ... that's the name of it.
.htaccess with a period in front of htaccess.
That file has special powers. It might be instructing your webhost server to
display some other page as the default. Don't mess with .htaccess, but if it
exists, copy and paste it on a post so we can see its contents.
Also, post the code/html source for the main page that is supposed to display.