We went back to study at a University when we were 39 & moved into a hall of residence we were there 2 years. It was the cheapest option.

We had cupboards in the kitchen that you could padlock, so they couldn't steal the cutlery & crockery etc, but we never found a way of stopping them stealing the refrigerated food. We tried all those signs, but they had no shame, even when we walked into the kichen one night & three of them were eating our food, lolol, they didn't care
The second year we were there we bought a little 2nd hand bar fridge & put it in our room. Might you be able to do that ?

The problem with them coming in drunk in the middle of the night when you have to get up early is insoluble, lolol. Maybe ear plugs, lolol.

Do they MAKE you stay in the halls there ? It is a free choice here, where you live, as long as you can afford it.
We stayed in the halls coz they paid for that on our scholarship, but if you had papers to prepare it was better to do them in the library.

When we went to Uni out of high school we lived at home first & then in a flat (appartment?). If we'd had to live in a hall at that age we would never haved coped.

Good luck (((((Rio))))) & rant any time, there must be large numbers of us here who have encountered these problems in many differing environments too,

you shoulda tried communes
there they steal your stuff & then you have to have 5 nights of 6 hours semi-political/therapeutic discussion about why they did it