Instead get a machine that works and upgrade it with more RAM, video card, hard drive and along the way you'll learn about what a desktop is, parts and connections. Starting from scratch is fine if you have a budget 2 or 3 times the amount of the parts as you may burn up this or that on the first try.
That is, unless you read more on the web or take a class. I don't write how to build a PC in the forum because that's on the web.
I know almost crap about pc's but i want to build my own can someone tell me how to get the right parts