If your university is anything like mine was, there should be no problem coming in with no experience. Even knowing you want to row in the fall puts you ahead of most people coming in. I had no interest whatsoever in rowing, but they kept on approaching me (I’m tall), until I agreed to go to an informational meeting. The rest as they say, is history.
Do some running, cycling, swimming, some type of aerobic exercise over the summer, get a good solid aerobic base to build on. Long, steady state. They will teach you how to row, so don’t worry about that. And they WILL get you in shape. Again, I wasn’t in fantastic shape when I started. A couple months of crew and I was in the best shape of my life. But if you’re already relatively fit and have a solid aerobic base, it may be a little easier on you.
Other than that, do a little research. Learn some terms (again, they will teach you, but it can’t hurt). Learn about the history of rowing; did you know it’s the oldest intercollegiate sport?
If you have any other questions, you can post again or PM me, I’d be happy to answer them. Good luck, and have fun. My years of crew are an experience I wouldn’t trade for the world. Congratulations on choosing the best sport (yes, I know I’m very biased).