Finding the right mentor for your business will really depend on what your goals are, what stage you’re at and importantly why you want a mentor. Are you looking for a technical expert in your field (courts/law/journalism), a business coach to understand how to build a small business in a smarter way (startup, or personal mentor to help push you to a higher level? Whatever reason, coaching/mentorship best works your when there is a strong personal connection and both parties are very clear on the expectations and outcomes.
There are professional mentor groups (paid for) but I’d suggest as your at such an early stage, try talking to your local council or regional development agency to see your options in your area. A lot of people find their coach/mentor through their personal and professional networks so keep actively networking there too. Are there any industry people you respect that you could approach?
A business startup is just really an early stage small business, usually setup different to the standard way. By changing your mindset to ask “how can I develop and test my business proposition and model quickly and effectively before I need to spend the money that I don’t have yet”. There’s plenty of great resources online to start with (e.g. search for Steve Blank/Eric Reis on Youtube), but also talk to your local regional business hub/incubator/accelerator about your options. A good place to find them and other resources is the NZ Entrepreneur site/magazine – https://nzentrepreneur.co.nz/ .
Good luck on the journey ahead!