Best to put this question under Technology and Science as there are sub-sections for Computers and Internet.
There are free places to host web sites so maybe look into that first (but I have no knowledge of how to do that).
If you want your own domain name you have register it and pay for it. Easy to do and not too expensive (few pounds). Many ISPs offer this service, I used Netcetera.
http://netcetera.co.uk/
Once you have a domain name you have to find someone to host it. You have to pay for this as well. There are hundreds of ISPs, and again I used Netcetra.
http://netcetera.co.uk/
Once you have your domain and an ISP to host it they will give you a userid and password which allows you to publish to your site.
Once you have the correct info you can select "Publish" in FrontPage, fill in the required fields, and there you are.
Easy !