The best area to walk around is there, with so much to do and see. You can visit many museums for free. I recommend the SDMA and walking around North Park.
Balboa Park
I love the botanical gardens, you can walk around for ages there is so much to see here! And great views of Encinitas and the beach.
San Diego Botanic Garden
I love this area and the farmers' market. You can also buy clothes and jewelry here. You can buy a meal and eat it by the beach!
Ocean Beach Farmers Market
Great place to walk around, eat, and shop if its your first time in San Diego!
Liberty Station
I love this area and old town! Also a must-go neighborhood when coming to San Diego.
Barrio Logan - San Diego
Good eats
They have many locations now around San Diego, this is a must try when you come visit! My favorite is the California burrito.