Just google “Mn form ST19” and a link to a pdf of the form comes up from the MN department of revenue. If they require a tax ID number, will they accept your social security number as if you were operating as a sole proprietor in your own name.
As a follow up there is a number to cal right on the form to register for a Mn tax ID number. Likely you would be required to collect sales tax technically which would mean you would need a sales tax account so you could report your taxable sales and pay the sales tax that you collected