... are they teaching you C++ or are you doing it for the hell of it?
If they're teaching it, let them tell you how they want you to do it as the course progresses. Otherwise you'll get puffed up on "already knowing the material" (even though you don't understand it yet) and end up missing out on the education behind the course.
That's the only way I can see you not having a choice behind the matter. If you're just doing it because you "want to release a C++ game", then you need to buy some books, study them, and then ask questions on here.