At the first visit, you will be thoroughly examined a detailed history of your complaint would be noted. you will be explained about your condition, the plan of your treatment, contents of your session and what to expect through your course of session.
It entirely depends on your condition. But is most cases 30 to 45 minutes.
Bring along your previous medical records, if you have any. Wear comfortable and loose clothing. Also carry a bottle of water.
The number of sessions would depend on your condition and the sensitivity of your complaint. You will be told about it in the first visit.