swiftly.nz is free forever for nz businesses. There’s a paid plan for $10/m to process payments online. The free version you can organise with buyer a payment method.
Very basic but perfect for what you need I think. Just load up all your offerings, customer adds to their basket and sends their order through to you and you take it from there. Share your store link to any social media you have and people will look at it and see all your offerings. Easy as!