I've only ever had 2 lessons, but that was later after I was already riding and started my horse.
I started on an older gelding, the sweetest horse that was really stubborn! But, he taught me patience and to be firm and not get frustrated with slow and stubborn old horses! Lol
My aunts mare was the second horse I learned on. She was well trained, but really heard bound. I gained a lot of confidence from her when I was able to stay on, even through her little heard bound fits. She was the first horse I ever cantered on. She knew how to do shoulder and hip yields, side passing and knew leads and lead changes, so, I learned how to cue for those on her. My mom would tell me how to cue for what and why.
My mom used to ride and compete in various English and western disciplines until she finished high school, so even though I never really had a trainer, she would give me pointers here and there. However, most of my riding was just trial and error, I would try to emulate pictures and videos from books and the internet. Overall, I would say that I learned more from the horses than people.
"Horses don’t have hard mouths, they have hard, stiff bodies. The softer you can get the horse through his body, the softer he will be in your hands." Clinton Anderson