HTML5/Javascript is nice to have if you plan on doing web development or making a game run on your website, but if you want to make games that run on PCs, consoles, or mobile platforms (phones/tablets), it won't do you much good. Its more important to get a strong foundation with some core languages first before branching out into web development. In my college program, we started learning C because it is really the "grandfather language" and so much software we use is written with it (libraries, O/S kernels, drivers, and so on). Its much closer to the hardware, so you have to really know what you're doing. C++ is C with lots of new features added on, so you'd be learning the "core" of C++ if you will. I would say stick with C/C++ and learn how to write a few different programs before moving on to games. Things like reading and writing files, doing complicated arithmetic, maybe a simple text word processor, etc.
After you're comfortable, learn at least one scripting language as well. I recommend Python or Ruby, two common languages in use today. (If you use Python, check out PyGame). Many games are written in multiple languages and each language communicates with the other, so you need to understand that. Over time, you'll find yourself learning and using more languages for different projects and jobs. I've used over 20 different languages myself after being out of college for ten years.
