Flash not working hoe can you tell if light bulb is burnt

Hi Tamara. Only a technical can tell, when opening the flash. (In your case the whole camera.) Sometimes, when you look very good, you can see the light bulb is black on one (or both) side(s).
But usually the technician would measure the high voltage on the capacitor and wheel the flash is triggered he will check if the thyristor fires. But not being a technician, please don't open the camera and never play with an open flash light, because the voltage even in a small camera can be very hight.