If you are in the market for a website, your first step is deciding which platform is best for you. There are many options out there but the main ones are Wordpress, Joomla, and Drupal.
This is probably the most commonly used system because it's the only one of the three where you can get your content online for free. There are limitations but if you just want to get some written content online, this (Wordpress.com) may be the one for you.
The difference between Wordpress and Joomla/Drupal is that Wordpress is hosted for you and you don't have to worry about the files in the background. The main downside is that nearly any kind of customization you want to do is a paid upgrade.
Joomla is the next most common among these three because while it does require you to install the Joomla site files before you can start posting anything, it's fairly user friendly. However, you do need some kind of hosting [a computer that is connected to the internet 24/7 where you put your website so everyone can access it] and that requires you to start paying right from the start.
Compared to Wordpress, a lot of customization can be done cost free but eventually when you want to start installing additional functionality like shopping carts, "contact me" forms, etc, you enter the pay for performance area. That said, there are many free options you can install that still work great.
Drupal is to website software what linux is to operating systems. It's the coders choice. It's described as having a steep learning curve but is very flexible and can become just about anything you want a website to be.
While Drupal can still be used as a blogging, website or e-commerce system (with pre-built add-ons installed of course) it's a little more complicated than Joomla, which in turn is a little harder to get started with than Wordpress.
In summation, I recommend you start with Wordpress if you aren't willing to deal with hosting and just want a blog to get some content out there.
I recommend Joomla if you are more of a tinkerer, if you want to add functionality features but want to try these things without paying for every single thing.
Drupal, is more of a blank slate so while it's super flexible, it's basically for pros.