I've never worked with Shopify, but I've been selling home&garden products on Amazon for about two years. It is really profitable. And convenient. There exist special services that help to meet all Amazon requirements. I work with the FBA Prep Center https://thefbaprep.com/FBA-Prep-Center. They do inspecting, packing, labeling, and shipping for me and make sure all match Amazon standards. So, neither my customers nor I worry about the quality of my products.
try for both.
while creating a Blog dont forgot to use both in the same website.
But if you are a beginner then start from amazon.
Amazon will help you in promotions and every thing you require for promotion is readily available with amazon. there is a community section in amazon. go there and ask questions and get answers as well.
Amazon is better than Shopify. It is one of the best platform to make money online and earn a passive income.
Always amazon is the best option to explore. However all the terms and conditions might have got changed due to COVID'19. We should go through these before taking any decision.