A .357 magnum revolver with a 6 inch barrel, preferably in stainless steel.
I know you said you prefer a semi-auto, but a revolver will be much less expensive, simpler to operate, easier to train on, and in .357 you can fire two different calibers of ammunition. (.38 special and .357 magnum)
IMO it's nearly the ideal choice for a first handgun.
Just my two cents. YMMV.
I have a Security Six that fires both .357 & .38 Special rounds. At home I load it with 38's in case my wife needs it. {out of concern for breaking her wrist}. Main issue issue is the trigger is too stiff. If you pull the hammer back manually and fire it's dead on. But the trigger action is too stiff and tends to pull off target no matter how slow and controlled I squeeze the trigger. Any ideas?