How tf do uni accomms actually work?

So I’m going to the uni of cardiff this year in September and have no idea how uni accomm works. Like especially for the common spaces, how do you like respect everyone’s space.

How is the fridge space allocated to everyone or everyone just comes in and declares the space they want.

How do I decide where to store my kitchenware or my food and do others use it, even if I don’t want them to.

I am truly confused about all this and would really love to know any and everything about uni accomm cause I myself have no idea about what to expect