Signs

This is the entrance to the petrol station on the main road. It's opposite a big secondary school, hence the sign about school students, and I have questions. Firstly, how would I (as a school student) know how many are already inside? It's not easy to see the whole shop from the door - there could be people hidden behind the shelving. What will they do if this order is breached? There is no mention of sanctions, but I wonder whether they reserve the right to do something, or not do something - perhaps not serve them? And would it be to not serve any of them or just the ones beyond the permitted pair? And what if it might take three school students to carry the Amazon package they are returning?

So many questions...