Does anyone have any suggestions or know how to make a newsletter from a athlete theme page? Which in turn i can sell digital products through the emails and build a loyal following?

Hey guys I'm here to learn how to sell digital products and build a newsletter from my Instagram theme page.

I run Instagram theme pages, my network is currently 2m+ followers. I’m here to learn more on making money & helping others grow if interested. Much love & peace have a good day. (I’m new)