How do I setup my HTML/CSS environment?

HTML and CSS are languages that are just interpreted by any web browser. They don't act like other conventional programming languages which are compiled into machine code or interpreted in a virtual machine. HTML and CSS can be written in anything - even as basic as notepad. These are grouped as "text editors" and can be powerful and help your workflow if you master one. The most important thing is you find an enviorment which is comfortable for you. The main ones I have grown accustomed to in order to benefit my workflow are Sublime Text and Notepad++. Both have great plugins and themes available to it, but Notepad++ is only available on Windows, where as Sublime Text is cross platform. Once you choose an environment, it's as simple as adding to the beginning.You can then type anything and when opened with a web browser you will see a very basic browser. CSS is similar to this.