If your going to be a caterer you need to be legal and legitimate. I am not in your area and I say this with much respect but, I get a little peaved at the weekend catering warriors that want to take the money but not pay their dues!
Catering is my only living and I have to work legitimetely & legally for me and my clients., why shouldn't you or the many others that wing it and keep their fingers crossed?
Let me say this for the sake of your future clients, do it properly and do it right. Know what your doing and you better have some experience beyond a few parties that will save your a$$ when the unexpected happens. If you are not a full time food service professional there is a lot to be learned.
You will need:
Servesafe if you don't already have it
Special events permits
The financial means to make the contracted event happen should you have a major breakdown of equipment or vehicle
And most importantly the passion, the talent & the desire to do it right!
Like i said, not trying to ruffle any feathers just adding my 2 cents