I'm traveling to San Diego for 3 1/2 days with my thirty-year-old daughter. Several questions:
1) Best area to stay in
2) Do we absolutely need a car or can we take not-too-expensive Lyft/Ubers around? Even to La Jolla?
3) We were thinking of hiking and/or kayaking in La Jolla. What are other must-see and do activities?
4) Restaurants to recommend? Daughter is vegan. They need not be vegan or even vegetarian restaurants, just vegan-friendly.

Thanks.

We went for about 4 days and stayed near little Italy on W. Ash St at the Best Western Plus Bayside Inn. Very convenient walking location to Little Italy and to the seaport area, to see the Midway and Star of India ships. We Ubered up to La Jolla and over to Coronado--I think it would have cost much more to rent a vehicle and park at a hotel. I do not feel it necessary to have a car there. Not a vegan, but many restaurants have their menus posted out front, or online. Very nice zoo, but we wished we had more time to explore Balboa Park, as they have many museums throughout. La Jolla had nice art galleries to walk around. If you don't get to kayak in La Jolla, at least go see Sunny Jim's sea cave--that seems kinda like a "hidden gem."

We stayed in La Jolla Shores for six days in October without a car, which worked really well for us.

La Jolla Shores is about a 30-minute walk from the main La Jolla area and, for our tastes, was much more pleasant – smaller, beachier and way more chilled. It’s also where all the kayaking goes from.

We had pretty choppy water for the kayaking which meant there was no visibility through the water and we couldn’t go into the caves, so that was a bust. I would definitely check before you head out and then reschedule if you can. On a clear day, we could see the leopard sharks just by walking waist deep out to the water.

We used Uber for everything and it was easy and not too expensive. Going from downtown San Diego to La Jolla Shores took about 20 minutes and generally cost $16 on Uber X. We even took Ubers to Torrey Pines for hiking.

On which, I can hugely recommend walking Torrey Pines. They also have free guided tours at the weekend which we caught. It was a tiny group (us, the guide and two friends of his who were visiting) and it really brought the park to life out of season. You can see a bit more here: https://torreypine.org/reserveinfo/

In San Diego proper, Balboa Park was hands down our favourite thing. We walked all the gardens and it’s a wonderful, relaxing free day. If we’d had the time, I’d have loved to see the wildlife reserve: https://www.sdzsafaripark.org/