Unfortunately, no! We're sorry about that - the hotels in the area don't offer shuttle service. We recommend downloading the Uber app so you can enjoy your night without worrying about driving and you can come and go as you please!
The night of the wedding we recommend you stay in Camarillo. If you're making a vacation out of the trip, we recommend that you find what activities you want to do and book hotels close by those things (like LA for all things LA and San Diego for all things San Diego for instance) then for Friday / Saturday night maybe book the hotel in Camarillo! For reference, Camarillo is about an hour from Los Angeles and 2+ hrs from San Diego. Things are a bit more spread out than they look on a map!
It will be highs of 60s (maybe 70 at most) during January and nights will get QUITE cold. We recommend lots of layers and bringing plenty of warm layers for the wedding - it's going to get cold that night!
Formal attire, but please dress warmly! It will be quite cold once the sun goes down. Don't let the state fool you!