What's your goal exactly? Depending on your goal there's a few routes.

If you want to produce compelling VR experiences then I'd recommend you download Unity. You should be able to start making real, valid prototypes for different types of VR interactions in under a week.

If you want to graphics then I might recommend you poke at http://humus.name/index.php?page=3D or https://github.com/bkaradzic/bgfx. But graphics isn't my specialty so my thoughts aren't the strongest.

If you want to learn C++ then... that's an interesting question I've not thought of before. Maybe I'd start with "Learn C the Hard Way"? http://c.learncodethehardway.org/book/ I'm not as much of a C fanboy/C++ hater as other game devs. I quite like C++11 lambdas and move semantics. But I hate boost and it's ilk. So starting with C and later adding a dash of C++ seems like a good way to start.

Just as a side note I will add a piece of advice I wish I knew back in the day: learn C++ itself, not what I did which was to think I was doing that, but actually really only learn MFC (this applies to any framework or library, Qt etc etc). Having said that, the STL will stand you in good stead whatever you decide to do.