Fresher questions about Oxford stuff

Hi. I have an unconditional offer (I applied post A level) to Oxford (LMH, History), and I just had few questions about some miscellaneous stuff.

Is the dress code for formal dinners suits or black tie? I've seen photos which suggest either - is it college dependent, and does anyone know what it is for LMH?

For a guy, could subfusc consist of shirt, shoes and trousers from a black tie suit along with a separately bought gown?

Do most people just get breakfast and dinner at college, and then go out for lunch? Also, on Saturday at my college only brunch is provided and on Sunday, only dinner - do people often cook together? Also, formal dinners are once a week at my college - do people often go to every one, or is it a 'special thing' you only do occasionally?

I know I've said a lot, and any answers are much appreciated. Thanks

A lot of this is indeed college specific, and you'll be explained all of this in due course by your actual college, a lot closer to the time, but I'll try my best to answer.

Formal dinner dress code is very college-specific, in general though, it'll probably be suit and gown, but not black tie, but it can be no dress-code.
Yeah, that passes for sub-fusc in Oxford, however, in general, most men choose to wear a dark suit underneath the gown as well. Personally, I'd say it looks a lot more "normal" to. If you wearing a black-tie trousers, you might as well wear the black tie suit as well?

Where people go for food is very college specific and depends a lot on the college. But as a rule of thumb, people in oxbridge colleges go for breakfast/lunch/dinner a lot more in Hall in College a lot more than people would expect, and really it just comes down to what your preference is. Some people go for Hall for every meal, some people go out for lunch every time etc. There's no rule for what everyone does. And yeah, of course, given it's uni accommodation, people are going to be cooking together.

Formal dinners are not something you are expected to go to every single time. You go when you have a reason to go. These may be because they're specifically designated for you to go (eg. Matriculation formal dinner, which you are obviously expected to go to), or if your friends all feel like going one time, say if it's someone's birthday, or you all miss fancy food lmao.