RORY: Oh, Henry, hi. Nice to see you.
HENRY: You too. What classes are you taking?
RORY: Shakespeare, physics, obscure Russian poetry.
Rory got a D for her first English Literature assignment, so it makes sense for her to enrol in two Literature classes to improve her grades further. One is the ubiquitous William Shakespeare, while the other is “obscure Russian poetry”, which doesn’t sound like a real subject. Possibly Rory is being facetious, and the subject is actually Nineteenth Century Russian Poets, or Modern Russian Poetry, or something like that. It may seem obscure to Rory, but probably isn’t – Chilton seems to cover the classics rather than anything left-of-field.
Rory has also enrolled in Physics, quite possibly towards credit in the next academic year, as she didn’t study Physics at Chilton in her sophomore year (Biology and Chemistry were her science subjects).
Henry is taking Trigonometry at summer school – just like Lane, this is his worst subject (an aversion of the stereotype that people of Asian heritage are gifted in mathematical subjects). Rory offers to help Henry with Trig, but we never see if she actually does so. It seems plausible enough since they’re both at summer school and Rory has experience in helping Lane with the subject.