I would look for a good used Ruger Single Six revolver at your price range, and also a .22 target pistol of your choice.
For absolute beginners, a revolver is safer. It's simpler to understand, and only fires one shot unless you deliberately cock the hammer again.
In the hands of an absolute beginner, an auto loader can be negligently discharged easily, since they only need to pull the trigger again.
Once they gain confidence and understanding and good habits, then switch them over to a .22 semi-automatic pistol.
It's the same strategy as training a kid to shoot with a .22 single shot rifle, before allowing him to use a repeater.
Once their habits are ingrained, then move them up to a center fire 9 mm, but not a lightweight one, as the heavier recoil might put them off.
Police and military have always trained raw recruits with .22 rifles, revolvers, and pistols first, before moving them up to the service arms.