Game development and engine devleopment are completely separate disciplines, at least in this day and age.
... to become "good" and "confident" to create games from scratch (engine, etc.)
If you're interested in making games then I would suggest you try out some of the different off-the-shelf frameworks and engines out there (Unity/2D toolkit, XNA, Torque2D, etc.). These take care of a lot of "boiler-plate" stuff for you, and allow you to focus on actual "game programming" (i.e. focusing on "what" happens, instead of "how" it happens)
It can be a good learning excercise to try to do everything by yourself, and this will definitely give you a solid foundation, but ultimately if you're doing anything bigger than pong/snake/etc. then there are huge benefits to using an OTS engine or framework.
I would suggest XNA + C# would be a good combination, as you'd still be working with a C-like language.
I already did something like that, but I want to jump into actual programming instead of using pre-created programs. I used to create mods for Warcraft III but I stopped, also learning how to build games from 0 not from 10% is more valuable, since you will know all the structure and it is more valuable in general!
Also age doesnt matter at all! I'm compelety mature and serious.