giving it a shot here.
you created a site collection at the root level of the web application.
I can see that your using https.
are you accessing the url of the site collection within the server or externally?
if internal it would be https://localhost:28080/
external would be https://mysitename:28080/
otherwise configure your host file within the server to access it by external name. Configure your AAM(alternate access mapping).
over the net externally you need to configure DNS entry for the external name otherwise you wont have access.... if you want to test it on your local pc you need to just update the host file.
make sure ssl is configured properly and lastly check 14 hive logs as that would pinpoint the issue if all other steps above has been done.