Purdue's campus is situated in the small city of West Lafayette, near the western bank of the Wabash River, across which sits the larger city of Lafayette. State Street, which is concurrent with State Road 26, divides the northern and southern portions of campus.
People who have sent you friend requests are visible by clicking the friend request icon in the menu bar. Friend requests you have sent are visible in your Activity Log, using filter Friends: (you may have to click more to see it).
The people you talk to on Facebook are usually those you have accepted as friends, but from time to time a stranger will send you a message out of the blue. Facebook has a message request feature, that sends you a notification if someone you are not friends with tries to contact you. But it turns out this isn't always the case. Facebook will only notify you if it thinks you might know the person. Anything else is filtered out as spam. I hear you cry.