Business plans can be easy if you understand whats being asked. The template Andy posted above is a good start.
The Regional Business Partners Network (RBP) offers grants to approved business owners to work with advisors, like myself, to work through and develop a business plan.
Here’s a link to their site: https://covid19.nzte.govt.nz/page/regional-business-partner-network
There are lots of providers inside the RBP can you can work with, but not everyone is guaranteed approval of a grant. Might be worth a try?