Trying to clarify. Disregard if it makes things worse.
1) Your web server has to be up and running. There has to be a website, ie something to show.
2) The computer has to be reachable from internet. Often this means that you have to open ports in your firewall / router. Standard port is as minimum 80. Often the router by default denies all external access into your local computer, that is until you open the ports. This is a good thing as the internet world is full bad boys wanting to take over your computer for their own dark usages.
3) Make sure you have a static IP adress (often costs extra from the internet supplier).
4) Now you can access the computer using your static IP adress, which might be spelled something like 192.10.10.1 (I made up a numer here).
5) You need to get someone hosting DNS to translate between your domain name ( mydomain.com or whatever) and the static IP adress ( 192.10.10.1 or whatever). I believe godaddy will do this for you, but you have to tell them the static IP adress.
// Gunnar