Question: I am new to Linux server administration. Is there any way to create a test server without having to buy a new computer or dual boot my Windows machine?
Answer: Yes there is a way, and virtualization is the answer. There are many paid virtualization options like Vmware, but if you want a free option that allows you to run Linux inside of a Windows host, VirtualBox is probably your best bet.
With VirtualBox, you can run any number of virtual machines, booting into Linux and testing whatever you need to test. You can even give the virtual machine network access to test an actual live virtual web server.
First, you should download the appropriate Linux distribution of your choice. If your server will use Redhat Enterprise Linux, you can still download CentOS for free and learn the same skills. Similarly, if it is running SuSE Linux Enterprise, you can download OpenSuSE for free. Then, you do not even need to burn the CD or DVD. VirtualBox will boot directly from the ISO and install into a virtual drive on your computer. Finally, you will be able to play and learn Linux with no real world consequences. With VirtualBox the opposite also applies. You can run a Windows server within Linux.