Access the super user account by typing su in the login, and entering the root password.

freebsd@RPI3B ~ % su
Password:

Add a user by entering adducer in the super user account prompt.

# adduser

You will be promoted for the Username: You want to enter the username of your choice.

Username: anyone

You will be promoted for the users Full Name : Enter the full name for the user.

Full name: That Guy

Leave the UID prompt empty

Uid (Leave empty for default):

Leave the login group blank as well, it will use your user name for the login group.

Login group [anyone]:

You want to add the user to the wheel group if you want them to be able to login to super user.

Login group is anyone. Invite anyone into other groups? []: wheel

Leave the Login class blank for default.

Login class [default]:

If you have installed zsh then use it, otherwise choose the shell you have installed, or default to tcsh.

Shell (sh csh tcsh zsh rzsh nologin) [sh]: zsh

Leave the home directory as is, unless you want to customize it, but this is standard.

Home directory [/home/anyone]:

Leave the home directory permissions as default.

Home directory permissions (Leave empty for default):

Leave Use password-based authentication as blank.

Use password-based authentication? [yes]:

Leave an empty password as no.

Use an empty password? (yes/no) [no]:

Reply no for a random password, unless you are creating the password for someone else.

Use a random password? (yes/no) [no]:

Enter your chose password and confirm it.

Enter password:
Enter password again:

Answer yes to lock out the account, so that you have to log into the account.

Lock out the account after creation? [no]: yes

Review the summary of entries and if correct enter yes.

Username    : anyone
Password    : *****
Full Name   : That Guy
Uid         : 1003
Class       :
Groups      : anyone wheel
Home        : /home/anyone
Home Mode   :
Shell       : /usr/local/bin/zsh
Locked      : yes
OK? (yes/no) [yes]: yes
adduser: INFO: Successfully added (anyone) to the user database.
adduser: INFO: Account (anyone) is locked.
Add another user? (yes/no) [no]: no

Enter no if you to add another user, unless you have more usernames to enter.