Not sure what your travel radius is, but there are the ones I know of.

LA City Wildcats is having a tourney.
DATE: JUNE 19TH, 20TH & 21ST
SITES: PARAMOUNT HS, DOMINGUEZ HS & LYNWOOD MS TOURNAMENT DIRECTOR: WAYNE THOMAS - 310-291-4715
EMAIL: Lacwildcats2000@aol.com

I know next level Championships is looking for one 10u and one 12u team for this weekend.
This tournament is for Division II and Developmental teams. You can contact ARC at 818-995-3761 as soon as possible.

SBA rebels has something this July at Citrus College in Glendora, www.sbarebels.org think it is middle of the month.

The Ventura heat always have a ton of things going too. http://www.venturaheat.com/index.php

I am in no way endorsing them as good tournaments or league, just passing info along.

Another resources is to check www.socalhoops.com, it is a basketball forum in Southern California, lots of teams post their events.

try
www.youthathleticsonline.com