Lift up on the wind knob, it should raise up perhaps 1/8" to 3/16" and latch in the up position (you might have to turn it slightly to get it to latch up) that should unlock the mechanism so that you can rewind the film. When your shooting you do have to push down on the little button beside the wind knob each time you start to advance the film to the next frame. Let go of the button once the knob starts turning or it might not stop when it has advanced one frame. Quirky little camera but fun
I have a couple of them, they can make some surprisingly sharp vibrant pictures.