I didn't have to wait long to find out. The cantor called the following week.
"Can you lead next Shabbat morning?" he asked. I felt my heart try to exit my throat. He would get me CDs of a previous service, so I could practice in the interim.
"And we will have a rehearsal," he added. "Call me on Monday."
That weekend was wall-to-wall Shacharit, as I divided all available hours between going over the Shabbat service and continuing to review the High Holidays. We arranged to meet on Wednesday. I didn't know if a rabbi would be there, too, or even which one I would accompany.