I'm guessing you are running a windows machine, and would like to have a look at Linux. If so then you could consider installing Cywin
Cygwin. Of course you must realise that this is just an Linux emulator.
Might be just as easy to create a dual boot machine, and install a proper disto :-) - I would suggest Fedora (did like SuSE, but not now).
If you really wish to look at a UNIX operating system, then I know Sun Solaris 10 can downloaded (I think it's now open source).
I don't think you going to get onto any UNIX servers via the Internet, too many (operating system) hackers.
PS - a few starter commands:
man man
man apropos
apropos keyword