I was never taught ladder safety. So I bought a ladder and learned by trial and error.
I learned quickly not to take safety for granted using a ladder. Just because you have the right tool for the job, we still need common sense when using that tool, and also be aware as best as we can at all times while using the equipment of what is happening and what we are doing, and also keep in mind what could possibly go wrong.

If we have at least 3 limbs on the ladder, like two feet and a hand, we are reasonably safe because we are well planted on the ladder.

An example of how it can go wrong for a person with only two feet on the ladder was when I was my very high garage and was getting a big steel loudspeaker down from the top corner. In order to pull the big speaker out of its resting place after unscrewing it from the beams I had to use both hand. It was one of those metal loudspeakers that you see on high poles at the likes of sports grounds.
I was at the top of the extended ladder and pulled on the loudspeaker which came loose suddenly and the steel transformer on the end of the wire came out from behind the loudspeaker and hit me on the forehead.
I remember everything going black, then I realized that I was swaying backwards because both of my hands were off the ladder.
The floor below was concrete and if I went backwards i would have been seriously injured of died.
I remembered swaying right out and I thought I was going all the way backwards and then suddenly I came forward enough for my hand to touch the ladder and grab on.
I was not prepared for the unexpected and nearly died because of it. After that and I had recovered from the concussion, I made sure to loosen the loudspeaker with someone there and did it all with one hand on the ladder.