What should ssh keys authenticate?
A person? a person physical computers? a person usernames?

I just spin up droplet, generated a ssh key pair from my pc, and added it to the droplet via the DO GUI for the root user. Now within ubuntu I’m creating a sudo user and will add keys to it. Should i generate a new key pair from the server itself and use those? or is it ok to reuse the keys from the root user?

The way i see it, if a create a new key pair for the sudo user, i might never again use the keys for the root user.