Ask HN: YC Work At a Startup advice?

I applied (and got invited!) to the YCombinator Work At a Startup event next week! It has always been a dream of mine to work at a startup (on the developer side) in the bay and/or SV, and I'm finally taking one step closer to making that a reality.

I'll be flying in for my first time to SF and really have no idea what to expect or do. I'd love to get more plugged in with the community and spend my day meeting as many cool people as possible.

Any advice on what to do for the day would be awesome.

(edit: spelling)