Congratulations on joining the CWU. There are a few basics I'd like to share here if you don't already know.
If you're interested in a certain division, specializing in that division is probably your best route. For example, Business you should keep shops open for long periods of time and show that you have read the Guide. You should also open a Civil Relations Centre in which you answer Citizens questions and hand out free request devices/fliers on CWU recruitment.
However, medical wise, try and spend some time with current Medical members in the clinic or get into it yourself.
If your worried about promotions, don't worry. Show us that your active enough on your CWU to be promoted and that you also have the skills necessary to join a certain division.
Business Leader - John Bourne (Me)
Medical Leader - Organizers until a new leader is found (Monkey with a Gun/Adam S)
Hope this clears your questions.