When did the spanish began settling in California?

The first of two land expeditions left El Rosario on Good Friday, 1769 under the command of Captain Rivera with Padre Juan Crespí as diarist. San Diego lay 350 miles ahead through, in Padre Crespí's Words was "sterile, arid, lacking grass and water, and abounding in stones and thorns." Two months later they arrived at their destination (14 May 1769). In mid-May, the fourth expedition with Captain Portolá and Blessed Serra left. Along the way they were forced to raid the Baja California missions for supplies and even then they ran out of supplies along the way. They were forced to live off the land and reached San Diego 1 July. As Portolá had ridden ahead, Blessed Serra was in charge when they arrived.

so the 1st of July, 1769 :D

hope this helps!