First Post-- Help with internship choice/career guidance (18 year old interested in IB)

This is my first post in WSO, and I am a senior in high school interested on pursuing a career in investment banking. I just turned 18 and I want to get an edge on my resume by starting to intern but I have a few questions--

First off, I am from California and my dad is currently a VP with Morgan Stanley. I could intern for him, but I believe that the way it works is that the broker you work for pays you personally for your service. He is fine with me working for him, but my question is: would it be frowned upon if my internship was for a parent? I am not yet in college, so I feel that it is an excellent opportunity; however, he says that if it would be better for me to work for someone else, I could work for someone else in his office. I would prefer to work for him, but if it is far better for me to intern for someone who I am not related to, then I will certainly do that--

Secondly, I would greatly appreciate any advice you all may have for someone in my shoes. I think I am going to major in finance, but I have not started my college career so anything that you wish you knew when you were 18/ anything you think would help me going forward (networking, majors, classes to take, etc.), I am all ears.

Thank in advance