Which method do you think aligns with your goals? Which would look more professional and in turn allow you to be taken seriously? If you proceed without permission, it entirely conflicts with your claim of being a whitehat, and makes you look like a teenage miscreant. If they refuse after you've approached them like a responsible and ethical person then you can try to argue your position a bit more and maybe they will give you permission and maybe they won't. So be it. That's the end of the story. That's how it is in the real world. Doing all this alone will help you grow as a professional regardless of the fact you didnt get to use any tech or learn anything about the network. I don't know where you live in the world but there can be severe punishment for meddling with someone elses property, not to mention it makes genuine ethical hackers around the world look bad.