Just smile, be earnest, and show the humility that you have so far. When the Dean finds out that you have a <3.0 GPA, s/he will probably go "oh", make a few pleasantries, and politely end the conversation.
Use this as an opportunity to find out about the med school application/admissions process, and med school curricula. It's still a learning experience.
Then thank your attending/PI for being so kind.