For those who want to open businesses, I feel like giving two different answers.
For those who are uncertain, not sure how and what they are doing but want to do it, I advise as already done to start from the very small, a shared space, a remediated room where it happens equipment to the minimum and devote time to study and understand what you do and want to do.
Different is the advice for those who are convinced and more knowledgeable, define your needs and find a work space suitable for production, produce, a lot, make mistakes, remake, specialize. Try to define yourself, to find a recognizable identity in what you make. Then along the way there will be time to figure out all the legal issues, how to sell, how to advertise etc...but without conscious production there is little way forward.