The Ministry Of Health-Manatū Hauora has a web site with the latest updates, information and advice on COVID-19:

COVID-19 (novel coronavirus)

https://www.health.govt.nz/our-work/diseases-and-conditions/covid-19-novel-coronavirus

The site has very comprehensive advice for anyone planning a public event (indoors or outdoors):

COVID-19 - Advice for public events and mass gatherings

https://www.health.govt.nz/our-work/diseases-and-conditions/covid-19-novel-coronavirus/covid-19-novel-coronavirus-information-specific-audiences/covid-19-advice-public-events-and-mass-gatherings