Your first port of call will be to get a food control plan from your local regional council. This can either been obtained through an at home kitchen or within a commercial kitchen.
Secondly I would start with setting up an instagram & facebook page – website can be set up later if you wish to sell online. Shopify is a great platform for this.
From there, approach the local markets that interest you & ensure that you have some imagery of your product posted on social media as they will likely want you to share these handles with them to do a bit of a ‘background check’.
Packaging & ingredient suppliers will come next.
Hope this helps!