I'm vegetarian and don't have access to a freezer.
I like to make ahead and have the same thing for a few days - it's fine to have one repetitive meal a day if you're having variety in the others!
I always have in:
Protein: beans (various kinds), lentils, chickpeas. Occasionally I buy cheese, and if I'm baking something, there will be eggs left that I can then eat
Carbs: pasta, rice, sometimes bread, bulgar wheat/couscous
More things in tins - tomatoes, tinned veg (peas, sweetcorn), tinned soup (if I CBA to make my own, which I do more often), coconut milk
Veg - I buy from the market each week
Normally some other things that keep well - naan bread, tortellini etc
If I'm not really cooking, I'll have carb + protein + whatever veg I have, just all thrown together on a plate. If I'm bothering a bit more, I'll make curry, a proper cheese sauce for pasta, something like that. (I eat a lot of curry!) Tortellini I normally have in and have if I really can't be bothered to cook or if I'm in a rush. A few times a term I go all out and make things like quiches, pasties etc (I make my own pastry). I also eat out quite a lot with my friends, or sometimes go to the buttery (catered food) if I want some food/it's the end of term so no point in shopping.
I think the key to cooking for yourself, especially sans freezer as I am, is to have lots of things that keep. Think tins and dried things. Anything else (veg!) you can get fresh, but if you keep fresh things to a minimum, you won't be wasting food cos it's going off.
I do often have packets of instant cheese pasta, for the express purpose of eating while drunk.