Most important: relax. I had the same problem during the first year in university. If you start:
"Keep[ing] track of everyone you speak to. Everyone. Write down what they mentioned they liked, who their family is, what matters to them."
you will feel or be perceived as a creep. Just relax. You are probably young. You need to find out who you are. Maybe you are an introvert or even a lonely wolf. You see the others socializing as if it's the most natural thing. You think you need to adapt. Try it, try being the extrovert, the introvert and anything in between. On the surface it looks like people like the extroverts the most but with time comes experience and the insight that it's not that simple. The most important thing is that you find your style. If you feel comfortable with yourself because you are confident in who you are you will see that you are surrounded by the people you want to spend your time with. Just take your time. Relax.