Ask HN: How to network in the startup community?

As a single founder/developer of an organic-solution tech startup based in SoCal, I will be in San Jose from 1/29 through 2/3. My purpose is twofold - [1] I will be attending a large event in the area over the weekend to market/promote my application, and [2] starting Sunday afternoon, I will have about three days to meet people and network in the valley.

Other than having applied for YC sessions W14 and W15 I have no contacts/exposure in the community.

My question: as visitor/newcomer to the valley, how can I meet people and make friends in the community during my upcoming trip? (meeting YC alums and/or other founders would be great - I'd would like to improve my chances, should I apply again, among other things)