Not nearly enough information to answer your question.
Which brand and model of camera are you using?
What settings did you use and which mode were you using?
Were you using the in-camera or an off-camera flash? If off-camera, which one?
When you clicked the shutter button what exactly happened?
If you're using the internal flash, was the flash turned on or off. There will be an icon indicating if the flash is turned off. The icon looks like a lightning bolt with a circle and line going through it.
If you're using an external flash, did you wait until the ready light on the flash was illuminated?
Okay, after writing all that, I see that you posted an answer (as opposed to an update to your question which would have been better) stating that the camera is a disposable Fufjifilm camera. Press the flash button to start charging the flash and keep the button pressed until the flash ready light is illuminated. If you do that and the flash still does not fire, then there's something wrong with the disposable camera.