I assume you mean how do you build a pc? if you're really not sure I'd suggest starting with a pre-built pc, there's many companies out there that admittedly at a higher cost than self-built will provide a pc built, set up with windows and usually under warranty too, as far as installing in your home, you'll have power leads, internet if you plan to connect wired or get a pc with a wireless adapter to connect to wifi, in addition to a pc tower/case you'll also need a monitor/screen, keyboard, mouse, ideally a mouse-mat under the mouse and should you so wish, a headset/speakers, as far as storage I strongly recommend having at least 2tb of storage, Ideally on an ssd instead of hdd as they're faster, quieter, and last longer.
hope this helps.