Taking flash photos of events, like family get-togethers, is easy. Here’s how.
Use a speedlight, i.e. a flash on top of the camera (not the pop-up). Put that flash on your camera. Aim it backwards, behind you, 45º up.
Now set your camera to manual mode, 400-40-4: 400 ISO, 1/40 sec, f/4.
(Adjust your exposure, if needed, until the meter shows about minus two stops. That way the ambient light is not too dark, not too light: just right. Goldilocks. Use aperture or ISO to achieve that (or, if it’s too bright, you can use shutter speed instead)).
Now the meter reads -2, And you are bouncing your flash against a wall or ceiling behind you. Then you get this: