Only one program can listen on a port at a given time usually. Something’s listening on port 443 (the standard HTTPS port), and when nginx starts up it tries to listen on that port and can’t. You can figure out what’s already listening on that port with commands like lsof or netstat, see here for examples:

https://superuser.com/questions/42843/finding-the-process-that-is-using-a-certain-port-in-linux

X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*

Probably the closest you’re going to get