This is very hard to define. I have all my servers on cloud locked down and can only ssh with keys (No passwords) and everytime I look at the access log, it just makes me sweat seeing all the "drive by" ssh access attempts using standard usernames (which I don't use) and even unstandard user names (like "mother", "suser" etc).
Almost like returning home and seeing unknown footprints outside your home door. You know the door is secure, the window is bolted and you have an alarm. But still it's unnerving.
Basic practices I follow:
Don't run services with a user that has root access.
SSH only with keys
Open up ports on Azure portal only for required services.
Check "last", "uptime" "htop" everytime I login.
----- [1] https://www.digitalocean.com/community/tutorials/how-to-set-...
Changing ssh port from standard (I literally forgot, is it 22?) to something else is one of those things you pick up in the field.
Usually only once you actually had to maintain production servers. And hopefully before some of the fancy things (e.g.: port-knockers) failed and locked you out :)
Changing port is super simple to configure and yet it cuts out 99.9% of noise (if not 100%) from brute-force attempts that otherwise might make you ignore alarms ...
Question 1: "Am I someone a sophisticated actor (e.g. nation states) would target?"
If the answer is yes, then congratulations—you're probably already compromised and will never know it.
If the answer is no, then you've very little to worry about as long as you practice good security habits.