I don't want to work for my dad's company anymore
Why don't you want to work for your dad?
My dad is a tyrannical boss and a very bad person.
Mixing business and family can be difficult so it is understandable if you want to separate both. Maybe your relationship with your father can improve if you no longer work for him.
I have a better idea, I will make business my family, and will own a company.
I think if you want to start your own business that is a great idea. It shouldn't be your whole life though.