Mention it in a blog post. A lot of bloggers get great initial results by working backward. Make a list of your top 5 or 10 blog posts. What things would be a natural fit in there? If it’s a recipe post, maybe it’s a few of the necessary tools needed to complete the recipe. Include your Amazon link. If it’s a potty training tale, include a list of books you read or potty training supplies you recommend. Still not sure? Google posts similar to yours. What are those people promoting within those posts?
However, there are three steps I recommend following before you settle into a specific niche and product.

In order to verify your identity, Amazon asks for a phone number which they use to make an automated phone call. When you enter your phone number, a pin number appears on the screen. The automated call will ask you to verify the pin number. It’s that simple!
You can select any topic that you like and start searching for products around that particular category. If you have more than one niche of interest, look for the one that provides a maximum profit. In case you are not sure, look up the categories on Amazon or Walmart.