Question: C++ or C#?
Answer: Yes.
If you're wondering where to start then it depends on where you're going. If you want to make something bizarre and performance intensive then go with C++. If you want to make something quickly that doesn't go too far off the beaten path in terms of computation then go with C#. In either case it's more about what middleware you want to use. If you like UE4 then learn C++ first. If you like Unity then learn C# first. If you like brain injuries then learn Java first.
Agreeing with Kylotan's earlier post, if you're asking this question then Unity may be a good place to start. It has a shallow learning curve but is still a professional-level tool.