Tire-fixing tools including a spare tube? (Obvious, but you didn't say so.)
Check the forecast for rain, for which you will probably want fenders, and to wrap your clothes in plastic bags. Probably warm enough in Davis, CA that you can just get wet and not worry about wearing rain gear, I'm assuming.
If not raining, sunglasses?
I use platform pedals too, but my ride's only 5 miles. Most others here with longer commutes prefer something more, but that's up to you. In any case, I recommend leaving a pair of shoes at work and cycling in shoes that you don't mind wearing out faster, like sneakers. Not required for the first day, of course, but eventually. (I used to sometimes ride in some loose-fitting loafers that I also worked in, but one day, one came off in the middle of intersection. Boy was that embarassing!
) If your laces are long, tuck them in.
Good luck, be safe, and have fun!