I have graduated from university less than 6 months ago and became a B.Eng in Software Engineering. I have moderate understanding of programming experience from languages like C++, Java and C#. But mostly on simple desktop and mobile applications. I've tried some simple Pong-like games but never finished even the smallest game.

I have a couple of nice ideas growing (IMO, at least...) in my mind but don't really know where to begin. 2D is way to go, of course, at the beginning. I just want to hear from more experienced game devs how they started out. Should I make a rough outline of the core idea and mechanics and start working on a prototype of core gameplay? Or should I just practice more by making Pong, Asteroids and that sort of games and get an understanding of those before moving on?

Thanks to all!