The fact that you had to ask this question means you are not ready to own a green horse. As someone else beautifully put, it is like asking how to be a nurse, cop, doctor.
What if I were to say, "How do I be a nurse? I know I am not really one, but there is someone available to answer a couple of my questions tomorrow, so I am going to the hospital to practice on patients.".
Now, you are likely thinking, how silly, it is a horse, I am not playing with people's lives! Well guess what....you are playing with your life. Horses can badly injure or kill you. Ask any horse person, by and large, the greener the horse, the more dangerous they are. That is why very experienced horse people still often send their greenies for their first few rides with an expert, and even after that, those horses are much less predictable than a well broke horse for those next few years
My mare was 4 when I got her, and I have many years with horses under my belt. She was well started. She *launched* me about ten feet in the air during an incredible bucking spree that first year, and I got injured. We perservered, now she is 12 and my best girl, glad I got her. But getting a young horse is always more dangerous than a well finished horse.
Please be fair to yourself and the horse and do not make the green on green mistake. You already know it is not wise.