I am posting because I have conflicting views to what has been said here.
- I don't think Java is a good language to learn first. This is also a common opinion of older more senior developers too. Why? Java abstracts you in a way that you don't get a clear idea of what is actually going on. (How and why the entire OOP language is structured the way it is, references, pointers, deallocation, etc.) I believe your principal multi-purpose language should be C/C++. (closer feel for why code is the way it is, c++->java easier than java->c++, etc.)
- I also don't believe you should be focusing on a myriad of different languages. You will gain a similar shallow understanding of each language, just now you're memorizing different syntax. Less critical thinking. Instead your kid should focus on getting as deep into one language as possible, or two if he must, and once he has a lot down, to then branch out. The best programmers don't know some of every language, but instead, after 15+ years they are extremely well versed in 3-6 languages.
In saying this, I believe if your child is up for the best learning experience to learn C++, a standard that will teach you immensely and allow you to branch off into most any language. But if you would like to start simpler, and maybe with a more interesting factor of playing with websites and animations to start with Javascript. Javascript can be learned on Khanacademy.com and Codecademy.com. C++ will be with a compiler and a good book on Amazon.