I did not read all the posts, I did see lots of great advice.

I have taught many to shoot, I use my Dad's old Ruger Single six in 22 for pistols and a Marlin M 25 for rifles. No recoil and no noise with ear plugs.

I teach safety more than shooting with new shooters, no finger on the trigger until ready to shoot, muzzle awareness. My wife said it was the same training she received in hunter safety. I said yep.

THIS IS IMPORTANT!

When you have a first time shooter you will find they do not have any bad habits that need corrected. This is good.

Work on technique and the basics of trigger squeeze etc and explain this to them. It does work. I have trained multiple girls who out shot their brother day one at the range because bro had shot BB guns or air soft or toy guns or Uncle bubba had let him blast a way at the dump.

New shooters are a blank canvas, paint the right picture.