which language is best for beginners to design a 3d game for android? LUA or javascript? among these which language is easier to learn from scratch ?
Well it all boils down to your experience, with which language you have worked before. If you have programmed in Java, C++ or PHP , then it won't be a problem in programming in any of the two languages you mentioned. However the most commonly used game development engine for mobile platform (Unity) supports Javascript right out of the box, so I would say learn Javascript. It will also help you in writing apps for other platforms and websites.
Besides if you learn to program in Javascript, it will help you in writing apps for other platforms like Windows Modern UI and Windows Phone apps.