It sounds like you're all over the map with what you intend to do, law school, cabinet maker, online sales. All the more reason to at least finish your undergrad studies. College exposes you to a variety of fields of study which enables you to make a more informed decision about a career option.
I'm surprised you dad is encouraging you to abandon your schooling in favor of running his startup business. You'd think he would recognize that you will be better prepared to run a business when you're a little older and more educated.
