We are structuring our consultancy firms what are legal requirements

We are five friends from IIT, started a company to give consultancy. We started as simple consultancy but Now, Our role is just attract more clients and provide to other associate experts. To facilitate, two of us started to develop technology for efficent functioning, other one started big marketing conference (Event). Now, we are in need to bring structure to convert into fair company. Any Recommendation. (We are in plan to hire the lawyer, but first like to learn myself, read case-study/some example and then hire right person)