I would like to start making games for PC.
I have attended all the available computer courses in my school to learn and understand programming.
what should I do now? Should I learn C++, even though it's going to be one hell of a language to learn? Or should I start learning the game engines like Unity?
believe it or not, game development is not about learning languages, engines, libraries, APIs, tools, etc.
ITS ABOUT BUILDING GAMES!
all those other things are simply means to an end.
so what you need is a game project. something of appropriate complexity for your current skill levels. that in turn will determine what languages, engines, api's etc to learn next.