want to go to a family function
Informal or non-reporting probation does not put any restrictions on the travel plans you describe. Just don't assume that because you are outside of California you can drive. All the terms of your probation will apply to you no matter what state you are in.
Mr. Kaman is correct. So long as the court didn't indicate you were prohibited from leaving CA as a condition of your probation, most of misdemeanor probation is informal, meaning you can do as you please so long as you don't violate the terms of your sentence.
DUI / DWI Attorney
Yes, you can leave the country when you are on informal probation. If you are planning on leaving the country, ensure that you will be current on all outstanding fines and that the trip will not interfere with any classes that you are required to attend.