Starting a construction company, and the requirements will vary based upon your state and even the country and city in which you will operate.
Generally, you should file the company with the State Corporation Commission as a separate entity.
You will also want to get an EIN (Employee Identification Number) from the IRS.
In many (most) areas, you will also need to be licensed, bonded and insured.
Check with your local regulatory agencies on specific requirements.
Firstly, I advise you to pay a visit to 2-3 accountants in your area. They'll have all the answers you need.
Secondly, I'd advise you to consult a lawyer for about an hour concerning all regulatory issues.
Next step is to start planning your business i.e. vision, strategic objectives in terms of sales, staff needed, suppliers etc.. Then, define your values and behaviors based on your processes, systems, and symbols.
These should all be included in your business plan. Once ready, go to the bank or investors (or use your own money) - get a project management software or app and start prioritizing and monitoring yourself.
Feel free to ask more questions about it.