Normally best selling products would mean high competition. The best is to do your own research on multiple platform. If you intend to sell in USA, look what people are buying there.

Then source from china using Alibaba or Aliexpress. This way you stand a higher chance to succeed. And even do private label products when the time come.

On Alibaba/Aliexpress, you can find the best-selling products through the sales and grades of the platform products.

Sales: The more items sold, the more likely it is to become a hot product

Rating: On Alibaba/ AliExpress platforms, the highest is 5 stars. The higher the rating, the easier it is for the product to gain the trust of consumers.

Take AliExpress as an example, select a category, enter the product name, then click search, and look for the check box that shows 4 stars and above to find the best-selling products. In addition, if you click the order button next to the best match, you can sort the products in descending order.

It takes some time to research the best products on AliExpress/Alibaba.