(wherever it says url.com, use your server's domain or IP)

Login to new server as root, then add a deploy user

sudo useradd --create-home -s /bin/bash deploy
sudo adduser deploy sudo
sudo passwd deploy

And Update the new password

Now login as that user

ssh deploy@url.com

Make directory .ssh on the remote server and log out

mkdir .ssh
exit

Push your ssh key to the authorized_keys file on the remote server

scp ~/.ssh/id_rsa.pub deploy@url.com:~/.ssh/authorized_keys