Ask HN: How do you find a mentor at a new job or a new place?

Hey HN. I was hoping to tap into the collective wisdom of the veterans.

So I'm just about to start a new job (graduated right now) in San Francisco for a well known mid-size company. I believe finding a mentor is one of the best ways to learn how to navigate the landscape, but I'm not sure what is the best way of doing that.

Any advice on how to find someone who can act as a mentor, either in your work or outside?