Zend certified PHP/Magento developer

Totally confused about Samba, new to Debian

I am trying to do a simple samba share for a home network. I want anyone on the network to be able to r/w to it.

I followed this but not sure if I followed it exactly correctly, since, as best I can tell, this guide demonstrates how to share a folder on the same disk as the main system, while I am instead seeking to share a folder on an HDD within the same PC.

Following these instructions I made it to this point sudo chown -R smbuser:smbgroup /share.

At some point after that command, this arose:

 sudo: /etc/sudo.conf is group writable
sudo: /etc/sudo.conf is group writable
sudo: error in /etc/sudo.conf, line 0 while loading plugin "sudoers_policy"
sudo: /usr/lib/sudo/sudoers.so must be only be writable by owner
sudo: fatal error, unable to load plugins

I found no information on how to fix this and so decided to remove samba completely to try reinstalling, however, the same message comes up when I run this, even as su.

I am now at the point where I cannot uninstall samba to start over, and I’ve been at this for about four hours, about to pull my hair out.

Can anyone kindly assist?