A lot of people, in fact, billions of people, are on Facebook these days, which makes it the largest social media platform. If you have an account, you can promote affiliate products on your page.
No one lands a hundred thousand visitors overnight. It takes time to build up your site from obscurity into an authoritative voice that consistently ranks high on Google searches and drives traffic to merchant pages. The most important thing is that you don't give up.

To truly understand how an affiliate works, look at what the affiliate does and where its traffic comes from.
This comes from authority websites that have their own programs. For large enough websites or big enough experts, they may choose to go with creating their own course. If this is a valuable course that is proven, provides great information, and they have built trust with a large following over the years then this can become a very lucrative partnership.