My Default Cube Won't Delete?

I’m new to blender and doing pretty well, but every time I attempt to delete the default cube it’s just replace with another one.

Also, is there any tutorial or guide that lists every keypad instruction?

Thanx.

Make sure the cube is highlighted (purple) and then press X, a little menu will appear asking if you are sure, hit enter or click on the only menu item on that box. The cube will (hopefully) disappear, if not then you’ve got yourself a bug.