2 Describe how you have connected it to the computer.
My guess, though, is that you can select the keyboard as a mid input device in, say, Reaper, play the keybaord, but get no sound. If that's the case, it's most likely because there is nothing to generate the sound within the DAW. Midi of itself has no sound. It is just a set of instructions telling something else to lay a note at this time, at this pitchm anbd forthis duration. You would need to load up a 'something else' to hear anything. The something else could be a virtual instrument.