You lost all your beginner fish, you should learn to keep them before moving to something harder. Its going to be far more beneficial to you and the fish. You dont loose everything in a tank without something being seriously wrong!
But it wasn't because I was unskilled, or the un-cycled tank.
Do you have any idea what killed them? I had no ammonia, nitrite, or visible signs of disease. I want to know if it was my fault, but until I know I don't think I did it. They just suddenly died.