yes, a personal license is an advantage, but not necessary, also my experience of how well enforced the "getting authorisation every sale" law is enforced is based on village pubs, city bars will probably be a bit different!
If you are wanting to be a bartender then I can help I took a bar/course on line that teaches you how to become a bartender. It was recommend to me, I ordered the course for 37.00. now I am a bartender in Cape Coral Fl. The bartending schools cost to much 400.00 or more for a class. I studied the bartending book and the drink recipes you can do the same. hope this info was helpful . bartendingexposed.com is the site I got my bartending book from you can order it right on line and study .