For programming in Unity3D choose either C# or JavaScript. I'd go for C#, because it's a full programming language and not a script language like JavaScript. Don't look at anything else at all, and focus on learning what you need for programming in Unity3D.
Also, the 3D graphics programming in Unity3D isn't very hard, because the game engine takes care of many things by default, and doesn't require extensive knowledge of 3D programming (very little, in fact). Especially easy to pick up when you already know general programming.
In Unity3D, the hardest part for non-programmers will be learning how to program.