You’ll be registering for classes, getting your ID card and setting up your accounts. You’ll be staying in the dorms.
It’s okay if you don’t go, but you may not get the classes you want.
First-Year Orientation is the best way to get started on the path to academic success at UC Davis. First-year students who attend Orientation are given priority registration for fall quarter before students who do not attend. Students are expected to attend First-Year Orientation because it improves their preparation for academic success and assists in their transition to the university. First-year students who participate in First-Year Orientation are better prepared, encounter fewer problems, and generally have a very positive feeling about their experiences at UC Davis. Plan to participate!
Southwest is your friend.
http://orientation.ucdavis.edu/first-year/dates.html