The worst advice I was given as a child was "treat others as you wish to be treated", because it is awful advice when moving in to a significantly different set of people.
It's a useful minimum surely? How else should you treat a significantly different set of people?
Yes once you get to know them, you learn how they want to be treated (mainly?) based on how they treat you and others.
Are you talking about using general formal politeness?
For example, I hate being asked questions multiple times. Therefore when i went to ubiversity, if I asked someone is they wanted me to buy a round, and they said no, I would not accept the answer. After some months I discovered I was considered tight, as the first offer is always refused, so "doesn't count".
Theres plenty of time over the ensuing months to communicate your preferences.
FWIW I wouldn't say theres a particular rule requiring offering to buy a round multiple times, so I'd have have been viewed as tight also, even if I was trying to fit in with normal convention.