Amazon Influencer Program Vs Amazon Affiliate Program Which On Is Better?

How can any brand or sellers contact these Amazon influencers for marketing their products ? Is there any way for this to happen asking as a brand owner ?

Just wanted to know if someone is completely new in the page, is it possible to be Amazon influencer.

Or we need to be Amazon affiliate first or earn some follower then only we can be eligible for Amazon influencer program.

Also wanted to know how people post content on Amazon about product unboxing and reviews.

I'm from India.

Your reply will be a great help for me.

Thanks 😊