I think the university’s international student office is a good place to ask about meds in particular. The health plans for international students, if done via the university, are NHS and in some places it can take a while to get a psychiatrist appointment. I definitely would not send any prescription medicine through the mail.
For phone plans, some get temporary SIM cards while they are there and others find it’s ok to use roaming plans from home, especially if they are mostly on wifi (and you should be able to set your phone settings so as not to accidentally use tons of cellular data for downloads etc), so check what your provider here offers for international.