I know this will go against the grain, but training is not required to be safe and effective. (It just helps the community feel safer thinking that everyone carrying around them, unknown, has been trained. But in reality, safety can be learned from reading and just being careful. You can learn the Four Rules of Gun Safety by reading. You don't have to pay to have a professional with credentials tell them to you. You can read about the legalities of shooting someone. There's an awful lot of info available.
And effectiveness? How many times has a store clerk fired a gun for the very first time when he grabbed the boss's revolver from under the counter and won the fight? How many times has a teen defended himself and/or his parents during a home invasion and won the fight? How about the people that successfully defend themselves at the gas pump? Don't ignore such stories. We've all heard them many times. They add up.
Experience, reading, and videos are the only training I've had. I've been shooting since the 70s, even rode 1500 hours on patrol as a volunteer with the Master At Arms Force on my off time (I was a Navy meteorologist) armed with a S&W Model 10 and a Rem 870 and didn't get any training. The Security Officer simply issued me the Smith. I made up my own training by signing out my weapons and some ammo and playing around off base in a remote area. (I did qualify expert.) Things were different back then.
Since retiring from the Navy, I've put over 200,000 handloaded rounds down range in competition and practice. I carry.
I think a training requirement is an anti-gunner fallacy meant to put the government between you and getting a gun. And, it is definitely driven by the professional trainers and their students. They make a fortune. (I think they provide good fun.)
What matters most is being safety minded, and being willing to fight.