what licenses do i need for my brand? , if i partner with license holders is that like me piggy backing off them? do I honestly need a license?

I found distributors and brands that are willing to ship to my B2B customers. I just handle the marketing and sales. But compliance and due diligence is not clear as customers will be ordering through my site. Do I need to do additional supplier verification? Where can I find the regulations on how each package needs to be shipped so I can request that from the supplier? Ex. Does each strain need to come with COA? Even if it’s a B2B wholesale order?