More complex to set up then a service based offer but much more scaleable once the work is done. The simplest version of this is using Shopify. You can utilise the free trial to familiarise yourself with the platform and start building out your website and making your product available. The idea here is that your products are available to anyone, anywhere, at the click of a button and the money goes straight into your bank account. Shopify have made it absurdly simple for people to get set up and selling almost instantly. There tutorials are far more comprehensive than my attempt would be so i wont even try. Once you’ve made an account they’ll automatically prompt you to complete which ever task is needed such as connecting a payment method (so people can pay you) and creating your first product.
The simplified process would look like this:
Create Shopify account > Connect payment method > Add product > Make sale > Ship order.
Again, you can use the free domain that comes with Shopify such as cutedogcollars.shopify.com until you’re actually getting some sales.