How Do I Compete in OTB Chess Tournaments?

I really enjoy playing chess and now I would like to compete OTB but I have no idea how to go about doing it.  In doing a little research I found that the USCF has tournaments but how do I receive an official rating in order to compete?  It looks like I have to join the UCSF and then pay to register in a tournament.  Is this correct?  How long does it take to earn a rating?  I could use as much info as possible.  Thanks in advance.