before i say anything ill say that you MUST learn atleast the basic c++ functionality before moving onto a game engine it will make things 100* easier and faster understanding these fundermentals that aside
the easier path for c++ is the enreal engine since this engine basicly can do most the coding for you
however if ur willing to go the long way opengl when done correctly will run anything much better then most engines can although likely take more time to create things
the other choice is usually unity which is great aside from the fact u must use C# or install a c++ dll which can be a pain at times
but all 3 of these engines/api's support multiplatform compiling to most if not all platforms and becomes a matter of personnel preference
there is however more engines which dont get me wrong are great but as a general engine with a good language u cant go wrong with any of those 3