Thank you for entrusting me with your question. At the first court appearance, the only thing that happens is the defendant enters a plea: guilty, not guilty, or no contest. If the defendant pleads guilty or no contest, the defendant is sentenced. If the initial plea is "not guilty", a new court date is set and the progress toward trial begins.
For a first offense, diversion is the normal plea bargain
offered by the prosecution; only if the circumstances were exceptionally offensive would it not be offered.
Unfortunately, if there is either a conviction or a diversion, the offense ordinarily cannot be expunged from an adult's record. However, a diversion is somewhat different from a conviction in that you can lawfully say that you have never been convicted of the crime in most employment and school applications since it technically is not a conviction. Law enforcement will know that it happened, so it is not truly expunged, but the impact is pretty minimal.
Lawyers do not have any magic powers--they can ensure that your rights are protected. In some cases it will have no effect on the outcome, but in other cases it will have a huge impact on the outcome. Personally, I think that any criminal matter more significant than a traffic violation warrants involving legal counsel. The good news is that if there is nothing that can be done, the cost will be relatively minimal.
I understand that you may have follow-up questions. Let me know if further clarification is needed. Thank you.