Ask about camera

How will I know the coordinates of the point at which the camera looks?
Also, how can I check whether the camera is looking at something?
P.S. sorry for my english, i use translator

I suggest that you should go through the tutorials, everything you need (and more) is explained there.

A camera is defined by its position and by its direction (and the frustrum, but that’s a bit harder).
You also have helper functions which translate 2D coords to 3D and 3D to 2D. Don’t have them in mind, but should be easy to find in the javadoc.