On the US Nationals 2011 page
(which I got to from the WCA website
), it has the following.
"No experience in WCA competitions is necessary, but competitors should be familiar with the regulations."
Based on that, I think that you could go to that competition. There's some more information on that website that you should check out if you're interested. Also, this page
on the WCA website has a list of US competitions on it.
Hope this helps!