This 4H Air Pistol Guide is a good document to use to begin to teach your child about responsible gun use. Recreational air gun shooting is a fun, inexpensive, and safe way to begin to learn firearm shooting fundamentals as well as cause and effect.
I like air guns as they are quiet, and can be safely shot in areas that centerfire pistols cannot be.
Beyond the training aspects, if you buy a air pistol like the one above, it may be possible to hunt small game without the need to buy ammunition. This, coupled with the low noise associated with air guns, makes an “adult” air gun a useful addition to a prepper arsenal.
I think it goes without saying that you should not buy an air pistol with the intent to use it for self defense, it just isn’t powerful enough. Also, you should not spend several hundred dollars on an air gun if you do not already have a good rifle, shotgun, and pistol as well as a few backups.4H Air Pistol Guide