Step 1 — Logging in as root

ssh root@your_server_ip

Step 2 — Creating a New User

adduser sammy

Step 3 — Granting Administrative Privileges

usermod -aG sudo sammy

Step 4 — Setting Up a Basic Firewall

ufw app list

ufw allow OpenSSH

ufw status

Step 5 — Enabling External Access for Your Regular User
If the root Account Uses Password Authentication

ssh sammy@your_server_ip

enter password

If the root Account Uses SSH Key Authentication

If you logged in to your root account using SSH keys, then password authentication is disabled for SSH. You will need to add a copy of your local public key to the new user’s ~/.ssh/authorized_keys file to log in successfully.

Since your public key is already in the root account’s ~/.ssh/authorized_keys file on the server, we can copy that file and directory structure to our new user account in our existing session.

The simplest way to copy the files with the correct ownership and permissions is with the rsync command. This will copy the root user’s .ssh directory, preserve the permissions, and modify the file owners, all in a single command. Make sure to change the highlighted portions of the command below to match your regular user’s name:

Note: The rsync command treats sources and destinations that end with a trailing slash differently than those without a trailing slash. When using rsync below, be sure that the source directory (~/.ssh) does not include a trailing slash (check to make sure you are not using ~/.ssh/).

If you accidentally add a trailing slash to the command, rsync will copy the contents of the root account’s ~/.ssh directory to the sudo user’s home directory instead of copying the entire ~/.ssh directory structure. The files will be in the wrong location and SSH will not be able to find and use them.

rsync –archive –chown=sammy:sammy ~/.ssh /home/sammy

ssh sammy@your_server_ip