LOL. This sounds more like a homework project than it sounds like a UNIX install, but I'll see what I can do to get you on the right path.
Typically, there's no "administrator" accounts on UNIX. Some "old guy" will probably start arguing with me about the wheel group, but essentially you're either root or your not. So, if you have the root password -- congratulations, you're an administrator :-)
As for setting up an account, you can pretty much just use useradd (I think it might be adduser on some systems, just to screw with dyslexics). Something like this should work:
useradd -c "First Last" -m username
This will create a user with the comment of "First Last" (usually their name) and a username of 'username'. The -m causes it to create the home directory if it does not already exist.
As for the system type, `uname -a` as you have already discovered will get you well on your way. I don't know if it works on Ubuntu or not, but I've always been a fan of `cat /etc/issue` for determining the install OS. It's actually the file that gets displayed when you connect via telnet (slowly going the way of gopher), but it usually contains the OS distro version.
To help with the rest of the commands, try something like this:
man cron
man 5 crontab
man passwd
man w
man 5 group
# (and if that doesn't help)
man man
That should at least get you on the right path (no pun intended).
</help with a flair of sarcasm>
-geis
Unsolved 
