This experiment should be done outside. Fire is very dangerous.
Remove the TOP of the propane nozzle, it should unscrew with a little effort. Next, place the top head of the propane tank (including what's left of the blowtorch) and turn it on SLOWLY. Bubbles should start to form, make sure they are as small as possible. A good way to ensure this is to keep the nozzle vertical, so that it presses into the bottom of the pan creating higher pressure.
Finally, when you've made a desired amount of bubbles, soap up your hand (or hands, if you have somebody to light the bubbles for you), grab some bubbles (ensuring you hold the bubbles PALM UP—otherwise they will burn you), and ignite them at ARMS LENGTH.