To create a new user on Ubuntu (Heron8)

adduser johndoe

To create a new group

groupadd barleyfarmers

Add johndoe to the barleyfarmers group

adduser johndoe barleyfarmers

The adduser command, when you're first adding the new user account, will prompt you for information pertaining to the account -name, phone, password, etc. If you want to change the password use the passwd command followed by the username for that account.

passwd johndoe