Anon,
Do check out the eating places at your university when you start for those days when you might not have time to prepare lunch beforehand. It always worth knowing what kind of food they sell on campus, the prices and where they sell hot food.
You might also like to find out if there are fridges to store a homemade lunch, where the microwave facilities are and where you can refill a water bottle.
You might have a short break between lectures or a very long one so it's good to prepare ahead especially if you need to print slides, return a library book or go to the post office!
With long lectures, there might be a break halfway through so students can grab a coffee/ stretch their legs, so you might also like to bring some additional snacks with you.
Hope that helps,
Oluwatosin – 2nd year student – University of Huddersfield