Shopify add to cart multiple variant with quantity

I have a website based on tourism. Following functionality to achieve: 1. customer can select all variant quantity. Eg: One service which is available for whole family with Adults and kids and if product has variant Adult and Child or Infant or Senior then product will show all variants and quantity selector. 2. In such case Adult quantity will be min 1 and all other will be optional and should start with 0. 3. Need to create a template so that on required product we can select the template and should not be implemented universally. 4. Add to cart should show Date of service and Added variants and same information must be sent on email to customer and admin.