I am a Global Project Manager by weekday and BBQ Catering by Weekend. GO FOR IT. You can pick-up the equipment as you go to make life easier and do larger events. I was using a Brinkman offset smoker $150 3 years ago and am looking to purchase a $17K Southern Pride SK1000 Smoker trailer mounted in 3 months (1000 lb of meat).
The beauty of doing weekends is you still have a steady income while you learn the ropes and make mistakes. The down-side is it is hard work so you farkin work all the time.
I would suggest a couple of things to start:
1) Visit your local Health Department and see what you need to be legal.
2) Get a buisness licence at the County Court House.
3) Look into insurance (BOND) for your safety and most Festivals will require a $1M Bond and Health certificate prior to serving the public.
4) See if the Health department offers Food Handling Classes. BBQ is consider HAZARDOUS food, and to keep everyone safe it is a good idea to know holding temps, washing and steralizing procedures, etc.
GO FOR IT and if you don't have a passion for Qing, you will soon know it.
Big Jim - Newnan, GA
Customized Lang Model 84 Longneck