Well your question isn't exactly clear but:
1) Find customers that are will to advertise your product as an affiliate - find ones that are your superfans - people that love your product as they'll be enthusiastic about selling it.
2) Advertise that you have an affiliate program - reach out to your existing customers, have a page on your site for "partners" or "affiliates". Share some of your Affiliates' success stories.
3) Have a proper Affiliate pack for potential affiliates to use - think of the why be an affiliate, how to become one and then have the Assets. It's so important to have a decent pack of assets so that the Affiliate doesn't have spend long getting your logo, your blurb etc.
4) Reach out and find influencers in your product space that you can convert to affiliates - Podcast hosts, Reviewers, Bloggers etc.
We have had pretty good luck using an affiliate agency. They are able to leverage pre-established relationships to get us opportunities we wouldn't necessarily have had access too without a lot of work on our own. They also manage incoming affiliate approvals and requests which takes a lot of the leg work out on our end.