Get your head wrapped around it - nobody is going John McClane against a band of BGs in a mall or wherever and defeating them unless you are training for it right now on a near daily basis. So much for your day job.
I have a slightly different perspective on that which I've mentioned before.
This is not chest-thumping. I carefully thought about it several years ago when the first mall shooter started firing down on the crowds below the balcony. Given the opportunity to deliver suppressive fire, keeping in mind the usual things about being sure of your target and what lies beyond, I will do so.
Even if it attracts fire to myself. And of course this is all contingent on whether or not return fire will endanger others near to me.
I have no death wish, but on the other hand, I've lived a full life, contributed what I could to society, and my offspring have been successfully launched into the sea of life. Hence my "different perspective" from those of you still raising kids and with half your lives ahead of you.
If my suppressive fire, delivered with my laser-sighted little handgun, can distract the shooter enough to save one younger person who has his whole life before him or her, that's the pro to the pro-versus-con decision-making.
The con is obvious and has been well-considered, as noted.
And all this has not changed because the evil-doers wish to die --even the home-grown balcony shooters and other mass killers wanted to die, and usually commit suicide when deadly-force resistance is offered anyhow.
I have thought this out carefully, and to repeat, this is not thumping of my 76-77 year old chest.
Anyhow, WRT the OP, I will offer informal instruction on firearms in their kitchen or living room, then, depending on their understanding of basic firearms safety and operation, take them to the range and allow them to try different firearms to get an idea of what fits them best. (Starting with an iron-sighted .22 rifle at 10-to-15 yards, of course, and with plenty of ear and eye protection.)
If all goes well, I wll then launch them into the sea of formal instruction and "let" them deal with it from that point on, advising them that you can't beat formal instruction from a qualified instructor.
All as I have done before.
Terry