Now this is a very good question and it honestly depends on what are you hoping to accomplish. If you are looking to just change colors and maybe a few things here and there, I would suggest just learning HTML and CSS. With that you can basically change colors, fonts, and any real styling of any wordpress website.

If  you are wanting to learn how to build themes, then this is definitely for the advanced people if you don’t know these web langauges. You can definitely take the time to learn these languages and definitely develop some kick ass wordpress websites.

Now for this, you will need to know HTML and CSS. Additionally, you will also need to learn javascript and jquery, because with these languages you will be able to make all the beautiful pop ups, light boxes, sliders, and so forth, happen with your wordpress website. Of course, you will also need to learn PHP because wordpress is built off of PHP. Once you learn the logistics and the very nitty gritty of how wordpress operates, then you can definitely begin moving forward with developing your very own custom theme.

What else should you know? Well, if you are somewhere in the middle, you can do what I call “skinning” a wordpress website, that’s where you take pieces of it, change columns, move stuff around, change colors, for the whole theme you found and liked and build something new out of it. Just make sure you don’t sell it because that would be copyright infringement and not to mention stealing.

With building a wordpress website, it can be simple if you are just wanting to get a theme, install it, and start blogging. But if you want to create your own amazing thing, you must learn some advance stuff, but no matter what you want to do with wordpress, there is definitely a way to create something that is just for you.