How do I get VR on my desktop?

I'm curious, how exactly does one go about getting virtual reality capabilities on their desktop computer? Is it a matter of purchasing specific hardware like a headset, or do I need to download and install certain software? Are there any compatibility issues I should be aware of, perhaps with my computer's operating system or graphics card? I'm eager to dive into the world of VR, but I'm not sure where to start. Could you please provide some guidance on how to get VR up and running on my desktop?