Healthy recipes for a school seminar?

tl;dr at the end and sorry for the (likely horrible) formatting, it does look fine on my phone but yeah, that doesn't really say anything.

So, I'm part of a seminar (a special class in German Oberstufe, the last 2 years before graduation, everybody is part of one, just the topics are very different) that focuses, among other things, on healthy nutrition. As a kind of project we decided we want to go away for a week in about a month, planning this entire thing ourselves (although always talking to our teacher before deciding anything important). Now, I was assigned to the group that's dealing with the problem of what to eat during that week. Because the seminar is focused on nutrition, obviously that would ideally be healthy, although it doesn't actually need to fulfill any conditions like being keto/low carb/vegan, it can be all of those though, just carnivore (=meals made of animal products, mainly meat exclusively) might be a problem.

Now, while I really enjoy cooking, I usually don't eat super healthy, also I thought you might have some ideas regarding what we might want to give a shot. One thing I need to add: we're not going to be able to go grocery shopping every day, most likely twice during our week. So, for now, I'm off to school, but I'd love to hear some of your ideas as to what we could eat when I come back.

tl;dr: We are going away for one week with school, I'm supposed to think of what we can eat, so I'd love to hear your ideas.

bon appetit