In most misdemeanor cases, so long as the statute on which your conviction was based has a jail term, i.e. 90 or 93 days, you risk incarceration for a violation of probation. This would include disorderly conduct.
In your case, the judge will have discretion as to whether to place you in jail. Usually, a sentencing judge will review a recommendation from probation. Thus, the judge's discretion is often exercised in conjunction with your relationship with your PO. If it's not too late, you should try to at least enroll in a class. That way, when you report to the hearing, you can at least tell the judge that you have not completed the class, by that you enrolled.
Any violation of a term of probation can end up you up in jail. It is up to the probation officer if he wants to violate you and then up to the judge what he wants to do. When you were sentenced the judge would have said “X number of days in jail, suspended upon . . . ”
Steven A Heisler, Esq
313 566 0000
Ultimately whether or not you will end up in jail depends on the judge, mitigating factors regarding the case (and why you did not complete the requirements), the probation officers recommendation and more.
In order to answer the question with more certainty, I'd need to know who you are in front of .