I hated it when people told me to "network" in college but being able to meet new people really is key post-college. Just practice talking to people -- anybody. People you don't know, people you vaguely know or recognize but have never really talked to. Try talking to people you don't know -- waiting for the bus, in line at whatever, at an event or party. They don't know you so you shouldn't feel pressure to be accepted or be afraid of being judged. You could be anybody, why does it matter what they think of you?! Make a point to talk to someone new everyday -- just force yourself to do it. Pretty soon you'll start to feel more comfortable and it will become easier to engage people. Practice it like you would any other skill.