Legal Question in DUI Law in California

Maybe.

It depends on many factors, like your blood alcohol level. Some counties impose at least 48 hours in jail, but others don't.

Probably not, but that is not a guarantee. Your attorney's job is to raise all available defenses with whatever admissible and credible witnesses, evidence and facts are available for legal arguments for various suppression motions, plea bargaining or at trial. If you don't know how to do these things, then hire an attorney that does, who will try to get a decent plea bargain for you.