All the regs. would vary by locality. So start at the town or county level.
There are many ways to get started on a small scale.
The most important advice I can offer is to keep your preparations simple and perfect them before you unleash them on an ususpecting public. Basic seasoning and simple sauces with familiar flavors work best and will appeal to the majority.
When doing it large, do it simple and do it right.
There are many exotic and tasty ways to prepare grilled and Q'd food, most just don't lend themselves to large scale cooking by a novice.
Knock yourself out playing around at home.
Buy a handfull of small instant read thermometers and check the temps on everything. Buy and use more ice than ever thought you would to keep cold stuff cold.