The most common and most likely answer to this crossword clue is the 6 letter word GET-GO
I've seen this crossword clue in Financial Times
G
E
T
-
G
O
More clues leading to the result GET-GO
Buddy explains!
The straight part
We know that "start in California" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case start in california = get-go.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does GET-GO mean?
GET-GO noun- The beginning.