You don't need to go out and buy thousands of dollars worth of camping gear, but get the essentials. A good tent will keep you dry in the rain. That's all you really need. Even though it didn't rain on us once this semester, Dr. Burk loves to tell the story of the time it came down in buckets and the class was surprised that they went and botanized anyway. The '95 class got snowed on in the Mojave.
Tents can get expensive.
If you're the typical starving biology student surviving on Top Ramen and Mac'n'cheese, see if you can borrow one. Chances are that this class won't hit any extremes that can't be taken care of with an average Coleman sleeper. The most important thing to have to sleep on is a good ground cover. The vast majority of the heat loss on a cold night is not to the air but to the ground. A ThermaRest or other similar pad keeps that heat from being sucked into the ground.