You really need to calm down and think before writing.
The JGO-Community posted constructive critic, which really could help you, if you want.
There can’t be any positive comment, if you have nothing to show, but an empty JFrame.
Also they told you, that Java2D is not made to create Voxel-Games (or even other games :P),
you should use a library, which uses OpenGL!
Also, don’t rush into 3D if you have almost no experience, start with small 2D games (pong, tetris and so on), else you will be frustrated, cause there are so many things to take care about and so many things you don’t even understand.