One of the most popular affiliate programs is Amazon Associates! If someone clicks on your link to Amazon and makes a purchase, Amazon will pay you a percentage based on the category/product they buy. What's exciting about this is, even if they don't purchase the product that you link them to, you will get a commission off of ANYTHING they buy within 24 hours of clicking your link!
For example, often a youtuber will post links in the comments. Such as "Here is the camera I use..." and people click their link, which leads to a $300 SLR camera on Amazon. Even if that person doesn't end up purchasing that camera... say they just take a look at it and end up buying something else completely unrelated, like a toy for their kids birthday, you will earn a commission off their purchase!
To get started, sign up with Amazon Associates (in addition to other companies, see suggestions below) and decide how you are going to run your affiliate marketing business. Do you want to start a niche blog and recommend related products? Maybe you could start a youtube channel reviewing products and link them in the description box. How about a daily email list of the top deals on Amazon? Or maybe you just want to send your custom links to friends and family, so they click on them every time they shop online? There are SO many different ways to make money as an affiliate marketer!
Here is the link to join Amazon Associates! While you're at it, look into other affiliate programs like ebay, walmart, best buy, and more! Sharing your affiliate links is an easy way to make extra money! You've got this!
BONUS: Click here for more ways to make money as an affiliate marketer!