Visudo

use as root command “groups” will tell you which groups you are in

visudo -f /etc/sudoers

Defaults=targetpw
ALL ALL=(ALL) ALL

You have two “modes”

Command mode – Press ‘ESC’ to access.
Insert mode – Press ‘I’ to access.
You’re always in one or the other.
To move the insertion point around, press ‘ESC’ and use the arrow keys.
Once you’re where you want to be, press ‘I’ and start entering text.
To delete a character, you need to be in command mode, select the character and press the delete key. (Note: not the Backspace key) You can do this in insert mode, but it does some funky things with the text.
To save your changes, in command mode, type :w and press enter.
To quit, in command mode, type :q and press enter.
To quit without saving any changes, in command mode, type :q! and press enter.

To add your login to the sudo group:

$ su

adduser mbc sudo

edit to look like:

%wheel ALL=(ALL) ALL

save and exit

Now test that it worked:

$ groups
mbc wheel

$sudo whoami

after password prompt should return “root”