How to become more of a person and integrate myself into social sphere?

As stated before, I'm going to ask this multiple times and
rephrase things a little to get the most helpful answers.
I
'm 25 and have no social life. I go to work, coexist well enough with people at work, I take classes at a university, just to learn and work my way towards a masters, then I go home and relax. Such is my typical life, though I have tried often to get out, maybe Barnes 'n Noble, have gone bowling, been to bars and hookah lounges, etc. I try to open my life for opportunity, waiting for something to happen, but to no avail. I see groups of people, not knowing how to join them, if I should join them, or even how these groups formed in the first place.

Further on myself: I don't have much of a lifestyle, not many passions to get myself out there, yet I know when I see others from afar, there must be a more complex and impressive psychological makeup, defining their identity, giving them their "personhood," as it were. I'm simply exist, however, going through life, work home class, but no social life that makes me a member of society. I'm currently looking forward to nothing, have nothing to talk to others about, and have no one with whom to share activities of any sort.

How do I, therefore, set myself on the path which engenders within me social capacities necessary to enjoy a life with people? Where do I go, what do I do, how do I find people who give my life a certain sense of relevance?

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