How to get mentor

[Isaac Howell]

I'm an 18 year old college student. I am thinking about asking a local real estate investor for an internship at his office. I have met him once before and he is a very nice guy. I am good friends with his daughter who works for him in his office. Any advice about how to respectfully and wisely ask him? I am willing to work for free, since what he can teach me will be worth much more than minimum wage. Any advice is appreciated. Thanks!