How can i host my own website?

[Jane S.]

I want few steps on web sites.
1st scenario: I have a PC and i have xampp installed on my windows 8 machine. i know it is not good place to host your site from, but i use it for practicing atm. But i would like to hear is it technically possible to hhost a real web page on my computer and how can one do that.
2nd scenario: If i by server machine, what would be procedure to host my website (do i need to install some web server operating system or i can install for example windows 7 or what?) If i pay domain http://www.mysiteblabla.com how do i set it up on my server?
Do i use my server for storing application and mysql db? do i use XAMPP or not?

It woudl be best if someone could walk me through procedure from beginning to the end, provided i am starting with only one laptop and a whole bunch of enthusiasm.

thanks in advance.