legally there are there type of business entatity in Nepal first one is sole trading second is partnership and company for single person you may choose either sole trading or private company. sole trading concern are less formalities and one person can start only one private compay have limited lialibility and more legal formalilty you can register sole trading concern in department of commerce with recommandation from chamber of comarce  or distrik association of industries and commarce minimum registration is firm and tax that is pan no if your business is more than 2 milion rupies than vat registration also compultary and some other licence is required for specific type of business such for banking company need licence form central bank for travel agency form tourism board

that much is enough for legal requirement for more need to know about your nature of business

have a happy selling