I think someone said it earlier...before you do anything you have to decide what type of website you want and what do you want the website to do IE: advertising, E-commerce, blogging etc. There are three basic elements to an online website...you will need a domain name (1) www.mywebsite.com
for example...then you will need the actual site itself with all its pages and images and functionality (2) and lastly you will need some webspace to upload the website to so that its visible online to the world (3)...start small with half a dozen pages or so and then build on it, which is what most people do.
Start with basic HTML and work from there...HTML is the easiest web language to create websites...failing that you could always employ someone to do it for you
Good luck with your venture