If you are visiting Santa Clara…fly to San Jose, and take the FREE bus that drops you off right in front of the main entrance. The airport is all of 10 minutes from Santa Clara University. It’s a shuttle flight from San Diego to San Jose.
If SCU is where you want to visit…I would suggest NOT flying into San Francisco. That’s not a convenient airport at all to SCU.
When we did our CA college trip, we stayed in San Diego. Drove to the greater LA area to see colleges…and spent two nights there with relatives. Returned to SD, and DH and the kid flew to San Jose and did the SCU visit. Easy peasy.