I'm not a genius & I've owned guns, shot competitively & handloaded my own ammo for 44 years. I've never taken a safety course or had any "Training."There’s a lot more to a safety course than you may realize. Have you ever taken one that was sanctioned and includes such things as; suicide prevention, domestic violence and keeping your guns safe, plus the safety part of the course? The course that we handle here in our area lasts about 4-4 1/2 hours. It’s pretty deep, but when the person leaves, they take with them a wealth of information and handouts.
My advice to everyone that takes a gun safety course is to always take a course that includes the things that I mentioned and to make sure to only take a course with fewer people, say no more than 6 people in the class, at least for the range part where you actually get to shoot your gun. There is too much chance of a mistake happening with too many people at the range.
When gun accidents occur, it's due to recklessness, stupidity & a lack of common sense, and NO safety course will convert an idiot into a responsible person. A gun comes with a manual with all necessary safety warnings. When I bought my first gun, I simply read the manual - just as when I bought anything else that could be dangerous.