Comission For Jeevan Tarang Do I Need Lawyer For Comission Agreement To Make It Legal?

Do I need lawyer for comission agreement to make it legal? - comission for jeevan tarang

I would like to establish a commission to the one company (I intend to help sell some of their products). Is it necessary to have a lawyer to be moral, or just me and the representatives of the company? Do I need to sign a witness?