Hi Teena:
That should be a fun trip, haven't been to Catalina in years, although our daughter and family go quite often.
Old Town is really nice, it is the old part of San Diego, with old homes etc that you can visit. Of course it has a Mexican
theme. They have Mariachi bands playing on the weekends and lots of shops with sort of international items. If you like Mexican food, try Casa de Pico in Old Town. You can sit inside or they have a large outdoor patio with heaters in the winter and it is very reasonable. If you are driving down route 5 there will be signs showing you the way.
Another place that is nice to see is Coronado Island, we used to have to take ferries but now there is a bridge. The Old
Coronado Hotel is quite a historical site.
The Island is beautiful with the beach on one side and the Bay on the other.
Another wonderful site is the Scripps Aquarium (spelling?)in La Jolla. We have not got there yet, but I hear it's quite the place with huge fish tanks and lots to see.
It's part of the Scripps Institute of Oceanography. La Jolla would also be off of route 5.
If you like shopping, Horton Plaza downtown San Diego is a unique shopping experience.
It has nook and cranies like shopping in a maze. They have the nice shops like Nordstroms, etc., and lots of little shops.
If you like Chinese food, the Panda Inn is the place for lunch, it is moderate.
Most people who come here opt to go to Mexico and I advise them not to. If you get in trouble there, it takes lots of money to get you out.
I hope this helps you to plan your day in San Diego and have a great time on your trip.
Jackie