Welcome!
As far as costs go that's going to depend on what you want to do as John already mentioned.
Suffolk County Master's License costs $200/yr. Figure $400 - $500 for Business Liability Ins as a minimum. As Doug mentioned as a Sole Proprietor Workman's Comp is not mandatory. For Medical Insurance figure between $800 and $1200 per month for a Family plan.
Good Luck to you,
Bill