College professor/low-level admin person here. Also parent of two college grads and one rising senior. So I have seen it from both sides but my advice might come more from my own experience many, many years ago than anything recent.
First, don't miss a chance to meet new people. Don't try to pick out who the cool kids are or who you would be embarrashed to hang around with. It isn't high school anymore, so the in-crowd either doesn't exist or consists of a bunch of people you will soon realize aren't as cool as they think they are.
Second, there is a good chance you will make life-long friends at college, but don't expect it to happen in the first semester. I look back at my experience and have seen it with my children and while a lot of the guys I hung out with in that first semester were actually good guys, it took a year or more before I started to really find my people - the ones I still text with and make sure to look up when I pash through their towns. The "you'll make friends for life" thing sets up false expectations and can lead to disappointment and an even stronger feeling of "I don't really belong here".
Third, don't be shy about introducing yourself to your professor or instructor. In fact, make a point of doing it early in the term. It is much better to do that than to have "I'm so lost and need help" be the first impression you make on them 5 weeks in. But as a corollary to that, don't be afraid to have the "I'm so lost I need help" conversation with them when that time comes. Falling out of the boat and never waving for the life raft generally leads to one outcome and it isn't a good one.
Finally, putting on my academic department head's cap for a moment, be as nice as possible to the people who are all around you making it so that you can worry about clashes and not other things. That means the housekeeping staff in the dorms, the people working the line at the dining hall, the facilities management folks, the department administrative staff, etc. Appreciate what they are doing for you and everyone else there.
The toughest part is when you get that phone call about something that you really can't (and shouldn't) step in and fix for her. When she can't get into that clash that is required this semester and has to wait until next year, or gets the jerk TA who won't excuse her missing a lab, or whatever. Give her all the advice you can, but let her be the one to fix the problem (unless it is something really huge).
I wish her luck and bet she will be fine. It really should be equal parts exciting and unsettling. I had a wise mentor tell me one time that real learning isn't happening in your clashroom unless you or your students are a bit uncomfortable - and often both. The same thing goes for all the other parts of going to college. It is a soft start to adulthood, but it is no start at all unless you get a few bumps that you have to learn how to get through.
I'll hang up and go back to listening now.