Alameda County Auction VS Norwalk

[Purnell C.]

I purchased a property at the steps of the Norwalk court house in the past and the process was seamless.  I showed up, waited for the bid, no one bid against me, I paid in full.  I went to the recorders office and that was it.  

For Alameda County, the website indicates you need to sign up with the auction website but I am confused about one two things:  When are the auctions held and can I show up if I am not bidding?  (I'd like to observe how it's run before signing up.)