[Lauxa]

I would say to pick a project and jump in. Go around and look at sites you like that are similar to the one you want to design. Get a feel for the tools they are using to build their sites. Borrow liberally from the sites you like as you build your prototype. Then start studying the borrowed elements one by one and replacing them with custom elements of your own design.

One thing you might like to do is install xampp on your computer so you can do all of your development locally. It is free and this way you will not have to pay for web hosting while you are learning. Also it is much easier to develop on your local machine than to have to FTP each file onto the server to test your changes. The xampp install includes Apache, PHP, and SQL, so I think it should work with most free CMS systems. If you are looking to get into ASP and .NET development, that is a whole another skill set and would require different tools.

Usually you will need at least some amount of graphics to do website design. Don't steal graphics for production sites. You can find some free or attribution-required graphics or buy stock images. The GIMP is a good free graphics design and editing tool, and I also like Inkscape for vector graphics.