Revv, you have to understand that each and every part of the computer (floppy disk drive, CD drive, screen, hard drive, etc. etc. etc.) has thousands (or millions) of individual components that make it work. There is no simple way to describe exactly how each part of the computer works. It is extremely complex, and I strongly recommend you learn the basics of electronics first. We will be very happy to help you here, but please understand it will take a long time to learn all you need to know to build a computer. Keep in mind that the first computer took decades to build and program. I admire your ambition and determination, but please know building something as complex as a computer can take a long time to learn to do.
I wish you the best of luck!
Regards,
Der Strom