All you need to do is be open-minded. When you meet people, ask for their pronouns. If you misgender someone, apologize.
Smith is historically a women’s college. It’s rooted in feminism and now there are many students there who don’t identify with the gender binary. Northampton is also the most liberal mid-sized city in the United States. You’re going to meet a lot of social justice-oriented people, and they’re all pretty cool.
The people in this Facebook group aren’t representative of everyone at Smith, though. If you’re really that worried, I’m sure you’ll find someone with views similar to yours.