You probably already know this – but UC San Diego is about 15 miles outside of San Diego.
I’ve stayed at the Residence Inn Gaslamp location and can recommend that if you want to be able to walk around to restaurants and that area—but considering you’re attending an event north of the city, you’re better off to stay closer to LaJolla. I’ve also stayed at the Marriot LaJolla and found it very nice – and there are nearby malls with nice restaurants (not just chains).
You don’t mention your price range – but there are LOTS of options at all price points near La Jolla. You can do a little searching on TripAdvisor to see other folks’ opinions.
Personally, if I were making a vacation out of it – I think I’d splurge and stay at the Lodge at Torrey Pines. It’s close to UC San Diego and is resort/golf course destination.
From the times that we’ve done some sight-seeing in San Diego we recommend Sea World and the San Diego Zoo. My husband loved the Wild Animal Park, too – but not my first choice. If you like ships/navy history apparently the USS Midway Museum is really excellent—but again, not my thing. I preferred Sunset Cliffs Natural Park.