See attached PDF for a schematic layout for you backyard. The design places a prefabricated trellis structure at the center that can be found at Lowe's for around $500 . That will provide some shade in the summer for some outdoor seating below. The patio can be formed of poured colored concrete that can be two toned and stamped with a desired pattern. Around, you can place ground cover of wood chips or crushed rock. Some plant options are shown for plants that are San Diego friendly on sheet one. You'll see the names of them on the bird's eye drawing. A second sheet shows a second layout that is more rectangular.
I've now loaded both PDF...so there should be two now.
Goodluck with your plans