is there a problem with Safari this morning?
My Safari seems to 'fail to open' due to Safari cannot connect to server... hmmm...?
MacBook, macOS 10.13
Given there are millions of combinations of Safari users, versions, systems, servers, websites, networks, error codes, ...
It is impossible to say. I think if there was some kind of universal problem someone else would have posted as well as you.
Try accessing another site. Try shutting down Safari then while pressing and holding the shift key launch Safari.