I would plan to arrive between 6:45 and no later than 7:15. Parking is limited on campus but you should be okay if you arrive by then. There will be signs to guide you on where to park, and it is very easy to find (very near front gate). You do not want your plebe candidate to be at the very beginning or at the very end, both of which will earn him or her unwanted attention. My DD arrived at 6:45 last year and was third in line. Regarding leaving, you can always count on bad traffic to the airport so allow more time than you think you will need. I will leave it to locals to give you more definite advice there.