You need licenses for plumbing and electric but carpenters/contractors are no license required. What a lot of guys do is take on jobs and then sub out the technical stuff to licensed and insured plumbers and electricians.

If you run a business as a sole proprietorship then you don't need an EIN or to register with the secretary of state unless you want to set up an LLC.

To be clear, this is not any sort of legal advice and you should always do your own research or hire an attorney if you have actual questions. Don't just take the word of random people on the Internet.