Selfies can be very tough. The focus is off on the nose and face, but comes into focus around the ear distance, so...the f/stop's probably too wide, and the focus is also off a bit. One tip is to focus the camera at a specific marked distance on the lens, say 8 feet, then tie a length of string to the camera, and put a knot at that exact distance, then string it out to get focus on yourself by pulling the string right to the base of the nose/eye area.
This is way under-exposed, so you need to figure out some way to get the flash more in agreement with the f/stop...not sure what kind of flash was used or what flash control mode was used. It's possible the flash is in an AUTO- mode (sometimes seen as a yellow, green,red,or blue color-coded mode setting on older, mechanically-regulated flashes that use sliding switches) which is supposed to be paired up with 1) a specific f/stop setting and 2)a specific ISO level for each individual AUTO-mode setting.
Flashes are all very different, and yet, at one level, all very similar. All you need to do is figure out how to get 'more exposure' in your shots made in this type of situation.