Morena. NZ is one of the easiest places to start and do business. Setting up a company is super easy, and does not take long. Same with getting your NZ Business Number. Things are more complex when it comes to the licenses required to operate as a retailer depending on the type of produces e.g. if selling alcohol or selling food there are regulations required to meet including the experience, background and standing in the community to be able to trade. Your question is very generic – my guidance would be to just spend some time on the web, do lots of googling and then maybe talk to an owner of a similar shop in another suburb or possibly find a friendly Council staff member to work through. Good luck.