I carry a category 3b Commercial Pesticide Applicator License as well as a 3b Comm. Pest. Business License.
I have my name registered (DBA) in the county I work in as a sole proprietor. I believe you should register your name in all counties you work in, if you operate in multiple counties. Right now I'm only concentrating on one so that's not an issue yet. Insurance is a must, but you already have that so you are good to go on that end.
You should be able to pick up some lawns before the season is over, which will give you a jump start for next season. Good luck to you.