I'm an aspiring 19 year old developer that has had experience writing numberous programming languages:
I self taught myself each language via trial and error, debugging and online documents and guides.
After learning my friend could make a text-based game in the console of a browser, I then looked up more information about programming languages, and where they were used. I started by learning to code plugins for Minecraft servers running Bukkit. This was hard because I didn't know at the time they were written in Java, I just assumed it was a way of writing them.
After figuring it out it was written in Java, I started to learn the language and doing so helped with the plugins.
So, now knowing basic Java, and how to make Minecraft plugins, I decided that I wanted to make plugins for other people, but I faced the issue of needing a place to advertise my services. I decided the best course of action was to get a website.
I didn't know any HTML,CSS or Javascript, but I did know that website builders weren't my thing. After using numerous websites, video tutorials and a bootstrap template I managed to create something I was proud to call my website. This website advertised my plugin service.
Intrigued how I created something that was on the World Wide Web for anyone to see, I later started by playing around with websites and with more information on how websites work. I could create a basic HTML and CSS based website from scratch. I then moved on to using Javascript to do things on my website and discovered that it wasn't to dissimilar to Java, just instead of putting X here you would put a Z there. That then lead to creating a website like the one here, just far less advanced.