I want to code a blog system. What language?

What coding language would I need to learn to code a blog system?
PHP? ASP? What are blog systems (like livejournal, blogger.com, etc) usually coded in?

Why I want to learn coding: to code a dynamic blogging system that supports "categories" (basically, tagging of blog entries), cause I haven't seen one anywhere..

about me: I'm an absolue newbie at coding. Did some HTML back in 1997. (And no..you won't see me post about my mood and what song I'm listening to, so please help!)

@all: thanks to the helpful (few..), and hilarious, so far!

I guess I'll start with setting up an apache server, then download an ebook about php, since it seems that's what everyone does to get a clue.
An explanation of why I'm going the lenghts to learn a bit of coding just to code my own blog system:

1. visit this page, it's a blog.
http://ecmanaut.blogspot.com/

2. See the pull-down-menu on the right, named "Topics"?
These are the topics/categories/tags which the author of this blog defined. Everytime he writes a new blog entry he tags it with one or more tags. Visitors of his blog can now choose the blog entries they're interested in. Now click one of the categories. You'll see the relevant blogs entries listed below the pull-down-menu.

But what happens to the page itself? Nothing. The visitor has to click the respective blog entries in order to read them
->What I want to code is: a dynamic blog system, that will rebuild the page with ONLY THE TAGS/TOPICS/CATEGORIES WHICH THE VISITORS HAS CLICKED.

Damn, it can't be that hard, it should be fucking, but it I haven't found a single blog system that allows what I want. Fuck shit cunt bitch anal.
Anyway, if you know of a free blog system that allows what I want, please tell me, and I'll forget about the whole coding thing. Joey Bishop.