Having been in similar situations before, a few pointers I would like to share with you.
a) Be careful which teachers you have. Many times there are a few choices for the class. Speak to people who have been at that exact school before. Some teachers will be more lenient when it comes to yom tov, others will give you no slack. Some will pick on you as the “Jew”, some will try to bring up controversial topics (according to the frum world they are, but many goyim see it as normal), and some will swear ect. But there are always decent teachers who will allow you to take make up tests, labs or presentations. Some will be polite, decent and use proper English. I have had both.
b)Look carefully at the courses you will be taking. Dont take any religious classes. Even if they say “Hebrew” in the course outline. Philosophy and anthropology should also be crossed off your list. Darwinism is seen as “set in stone as fact”.
c)Prepare yourself mentally to answer people’s questions. There are those who are curious because you are different and then there are those who are Frei/searching and desperately need your help. Why do you wear long skirts and sleeves in the summer? Why a Yalmukah/tzizis? (for all the guys reading this post. you said you went to seminary so I assume you are a girl). Are you amish? (I was asked this once…along with “what church group are you a part of?) Do you believe in Yushka? Heaven? Gehenom? (they will use the secular terms).
d)Be prepared at their language and dress. Ignore it and DONT CHANGE YOURS. Jews in mitzrayim didnt change their names, dress or language. Continue speaking as you do now, dressing as a good seminary girl. Wear a long sleeved blouse and people look at you differently. Dress nicely and with a certain self-respect and people treat you differently. (in a good way there).
e) make a border around yourself. Dont allow people to be too friendly with you, especially those of the opposite gender. Dont be on a nickname basis with them. Dont hang out with them. Homework help in the library is one thing, but sit across the table if you are uncomfortable with them and be in the open/in clear site of other people.
f) write yourself a letter now, before the semester starts. Ask yourself who you are, what you stand for, and what are your sensitivities. Read the letter to yourself often, its your Igeres Haramban in a way, to keep you on track.
If you have a specific issue or question that you need help with, just post it and I’ll try to help. I have been there and know what you face.