Odd Events on calendar from unknown third party?

My calendar has been hacked or compromised in some way. I have odd things on the calendar about an event lasting weeks to called Telehealth for a handsome husband..Then another one was there last week. Can’t remember what it was. The events can’t be deleted. When I go to settings- calendar -it shows an outlook calendar and an iCloud calendar. I don’t remember adding an outlook .How do I delete these bogus events and prevent them in the future?