Where do I begin?

Back in 2007 I had a search angel help me reunite with my sisters and was wonderful! She was fantastic. Now, my bmother had passed the year before but i couldn't find a name for him. Was stationed at army base in Pittsburg/Antioch, CA and met while she was separated. Would have been in area in 1960 for sure. Where do I look? No longer a Camp Stoneman base there any longer. Any ideas please? Thank u.