The sentencing date itself is public information and the easiest thing to track down. Contact the Clerk of the Court in the county where the charges were filed. That office maintains the court calendar and can tell you when the sentencing hearing is scheduled. Most clerk offices can be reached by phone, and many counties now have online case search portals where you can look up the case by name or case number and see upcoming hearing dates without making a call.
What happens at that hearing is harder to predict, and anyone who tells you otherwise is guessing.
Before sentencing, both the prosecution and the defense submit sentencing memorandums to the judge. These are formal documents laying out each side's recommendation for what the sentence should be and why. The prosecution argues for what they believe is appropriate given the charges and criminal history. The defense argues for leniency based on mitigating factors, character, circumstances, and anything else that might move the needle. The judge reads both.
The judge also has to work within mandatory minimum guidelines where they apply. Certain charges carry a floor that the judge cannot go below regardless of how sympathetic the circumstances are. Those minimums are set by statute and are not negotiable.
Beyond that, nothing is certain until the judge speaks at sentencing. Even experienced defense attorneys who have appeared before the same judge dozens of times will tell you the outcome is never guaranteed until the gavel comes down. The best information available before that moment comes from the defense attorney, who can give your friend's family a realistic range based on the charges, the guidelines, and the judge's history with similar cases.