So I want to start designing

[Gaijin]

Start off with HTML...
w3schools.comis a great place to start, html is not hard to learn and with enough training you'll not need more than a month to learn it.

The next step would be CSS...
w3schools.com again, has enough information on css also, it will bring you into those 2 languages.

Now, it depends what "skills" you wish to expand, yea.. just like a game...
Basic knowledge in HTML and CSS is needed for web developing, among other things. You can however invest more time, experimenting with HTML/CSS, gaining more knowledge....

Web Applications mostly use some kind of Server-Side Scripting Language, PHP is the most popular one, while python for example can be used for server-side scripting.
So you'll need to learn how to, write scripts which are executed on the server, in order to parse and format the outputs of the script, you will use HTML/CSS to style your output (presentation).

JavaScript would be used to make your application (site) more, dynamic...move, resize, drag...etc...
JavaScript and PHP have pretty much the "almost" same syntax, so by learning one langauge you can already code with the other...
However, PHP is the Server-Side, which is more important then effects, so I would recommend starting in following order;
HTML -> CSS -> PHP -> JavaScript

HTML and CSS shouldn't be hard to learn, PHP and JavaScript in other case, this can take you much longer, 6 Months and up. (Basic Knowldege) o.O
w3schools.com, has also examples and tutorials for PHP and JS.
w3scools is just there to introduce you to the languages and their structures, once you go through their articles it's up to you to expand and improve your knowledge... (skills/gain exp)
Read other scripts on the net, tutorials and write a lot of your own stuff, just try things out and learn from it.

http://www.w3schools.com/tags/default.asp
http://www.w3schools.com/html5/html5_reference.asp
http://www.w3schools.com/css/css_reference.asp
http://www.php.net/
http://www.w3schools.com/js/default.asp

http://www.css3.info/