Is he undeclared in the College of L&S or College of Bio Sciences?
You probably already have this info, explaining some special advising, but just in case you don’t.
I also want to mention that the UCD Freshman orientation program is rather thorough, in case he doesn’t do a Summer Session. The students can move into their dorm a couple of days before Orientation starts, and then they have 4 days in a group of about 20 students, learning about and touring all the places on campus. Great way to meet new friends in the small group.