Onboarding Suppliers for Dropshipping Business

I have a dropshipping website related to selling indoor/outdoor fountains (https://thesunrayfountains.com/) and I'm looking for assistance in onboarding suppliers for this product. I have a list of suppliers who sell this type of product and need help with contacting them (via email/phone/message etc.) explain them the value proposition of my online business and building a partnership with those suppliers so that I can sell their products on my website