I tried your instructions several times without the expected result. Tried it with double spaces between the commands, which looks to be correct, also tried single spaces in case I was misreading something.
The number of spaces don't matter, I just double spaced the command so you'd notice the spaces.
Technically, it did work, because barb10jim09 is now a member of the admin group, but that hasn't solved your problems.
Do you think it's time to remove one or both of the users and start over?
I think it is time for a re-install. It's easy to mess things up when you are just starting with linux. I think I needed three reinstalls in my first week because I kept playing (& learning!) until I broke it.
Plug everything in (router, printer etc) and turn it all on. Reboot from your CD and reinstall.
Once you have done that, the first thing it'll want to do is fetch updates - let it, then reboot, then add your other users and start configuring things.
Remember the first user registered will have admin and sudo privileges, the rest will have the privileges you assign them when you create each additional user, so take care with these.
On my 'buntu systems, (6.06, 8.4) the network comes up at boot, and all users can use it. I don't have to turn the network on, it's just there as long as my ethernet cable is plugged in.
Let us know how it goes.