I think your best approach is to start with a language that you are familiar with. Learning about game development requires you to be at ease with your tools and to focus on the specific challenges that comes with the field, rather than the language.
Start with the fundamentals: how do you manage your game loop, how do you load external resources, how to you save and restore state, how to you manage your artificial intelligence and which pathing algorithms are more efficient for your needs? As you start learning, you'll see architectural and functional patterns emerge.
As your project grows, you'll start tackling new challenges such as networking, optimization and the usage of frameworks to make game development more efficient.
So in general, I'd say go for something easy that you are comfortable with, like Python (there are wonderful libraries and frameworks available). Learn the core fundamentals there, and from then on you can explore other options like C++ (seriously used in the industry) and their existing frameworks. I'd stick to non-mobile, non-flash development for now, as developing in those environments introduces extra challenges and constraints which are fairly specific.