If you mean the 1st stage AOR then the next step is sponsorship approval.
If you mean the 2nd stage AOR then the next step would be receiving a passport request in the mail and your status changing to "in-process". Which order those two happens can vary, but usually it is passport first, then in process.
The medical request is not a "step" in that the medical should have been submitted as part of the original application package. If it was, and it is still valid, then you will not receive a medical request. If you submitted one and it has expired then a re-medical will be ordered. That can happen any time in the stage 2 process. If you didn't submit a medical with the application then they will request a medical which may happen any time (stage 1 or stage 2).