Surprisingly enough, there is no fully effective answer to this question. If you parse the wording on the PTB application for license, it asks for convictions. Juvenile adjudications of guilt are not convictions. However, California State licensing agencies and their analysts are not necessarily knowledgeable on this fine distinction in the law. I have seen any number of State license applications delayed by unnecessary time and process -- almost 2 years in some instances --- while the issue of the State's ability to consider juvenile adjudications and the issues re disclosure of them got sorted out by lawyers who should not have been necessary for the applicant.
The most critical objective is to avoid an answer that the State's analysts will think is deceptive, even if the analyst is wrong. Responses such as "No adult convictions" or "No juvenile criminal history except as sealed by order of the Superior Court" can be effective to prevent any hint of deception attaching. But, even those answers may cause the application to be delayed for further investigation.
Since you are just beginning PT school, my suggestion is not to worry about this. The issue is addressable in all events with a brief attorney letter at the time of your application, and State analysts become increasingly aware of the specific legal issue over time. This issue is at worst a hassle and not a reason to change your career plans.
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As I recall, a PT license asks for convictions. I would not sweat it too much right now. If issues arise later, counsel should be able to rectify the situation or untangle the oft-occuring glitches.
The most important thing in my opinion is to study the language of the question, and then answer it accurately. for example, if it asks for convictions, notwithstanding any expungement pursuant to PC 1203.4, and you have had such an expungement, you would have to so state. the purpose of the juvenile sealing statutues is to provide even more protection than for an adult expungement. and as another attorney pointed out, a juvenile is not "convicted"; the allegation is "found true". so if your answer is ever questioned, you have good support for your response.