Do you think a judge would allow a MINOR to appear in court with no lawyer?? There are probably laws against that as well.
Err... In Michigan, the answer to your question is a qualified yes. Minors have the right to counsel if charged with delinquency - that is, conduct which, if committed by an adult, would constitute a crime. It's a pretty famous SCOTUS case called In re Gault. However, Gault left open the question of whether juveniles can waive that right like adult defendants can. States have split on the answer. Michigan apparently allows it, but only after a review determining that under the totality of the circumstances, the juvenile understands what he or she is doing.
However, all this may be moot. Michigan defines "juvenile" as "under the age of 17". Juvenile delinquency cases are handled in family court. If you were 17 when you committed the offense, then what you have is an adult criminal conviction, which is a more serious matter.
So, you need to be clear on your terms. Were you adjudicated a delinquent in family court, and/or diverted under a juvenile program where adjudication was withheld? Or were you diverted under an adult program? Or were you convicted of an adult offense?
This forum isn't really the appropriate place for at-length legal discussion. My sage advice is the same as it usually is - consult an attorney licensed in Michigan (which seems to be your home state, or the state where this occurred. If I'm reading things wrong, then consult an attorney in the state where the offense/conviction/adjudication/diversion/whatever happened.).