Create and Grant Sudo Privileges to user

note: already signed in as root user, if signed in as a non-root user, add sudo before the cmd

Add a new user

$ adduser <username>

Give the new user a password

$ passwd <username>

Grant Sudo Privileges to a user

Make sure the wheel group is granted sudo privileges:

$ visudo

Uncomment the second line as following:

## Allows people in group wheel to run all commands
%wheel  ALL=(ALL)       ALL

$ gpasswd -a <username> wheel

Copy ssh public key to the user account

$ ssh-keygen -t rsa # only need if key is not generated before
$ ssh-copy-id <username>@<ip addr>

Ref: How To Add and Delete Users on a CentOS 7 Server