Hello James,
You can test the client/server functionality by just launching the server and the client on the same machine, and connecting the client to the localhost (IP 127.0.0.1).
You can also install a virtual machine. Have a look at
http://www.virtualbox.org/. The idea about virtual machines is to install an operating system over another operating system, obtaining a
virtual machine.
VirtualBox is very easy to install and configure.
If you have connectivity problems with your virtual machine you can use a VPN (Virtual Private Network). An easy one to use is
Hamachi. Have a look at
http://www.hamachi.cc/.
I hope this helps,
Jar