How do you find a roommate to dorm with if you do not have facebook or social media? How do they match you up?
You can usually meet people at orientation. Also, a lot of colleges have a quiz that will match you up with someone based on interests/sleep habits/cleanliness. If not, it’s usually just random selection.
They usually have their email address on the residential life website. Colleges normally have these Reslife sites that show you everything about living in the dorms. You can contact them through your school’s email.
If not, then you can always wait until you move in. Then, you can ask them for their social media or contact info.