If you’re planning on relying on SEO for traffic which most people do, it’s all about finding keywords where people would be interested in purchasing an affiliate product, and analyzing the competition of each of those keywords. Back when I was promoting Genesis themes, I saw hardly any articles about “Genesis eCommerce themes” (when I Googled it) which was a popular keyword. I got myself #1 for it. For SiteGround and StackPath, I saw opportunities to write articles on “settings” for each cache plugin (W3 Total Cache Settings, WP Fastest Cache Settings, WP Super Cache Settings, etc). After researching these keywords I was confident I could write better tutorials that the ones out there.
Getting views on YouTube can take much less time than getting traffic on a blog. It’s all about the content and video SEO. Make sure you’re researching a good keyword for the video, writing a nice title, creating a nice custom thumbnail, long description, timestamps, etc. If you are good at making videos, holding people’s attention, and finding a solution to their problem, you should be good.

You could also opt to use existing websites for making money. These include both active income and passive income methods. For example, you could sell some used items or invest in creating some digital designs that then can be sold on merchandise. Again, devote a sizable portion of your time to passive income so that you can slowly build up earnings that will arrive on autopilot without any extra added effort. 
Once you have the affiliate links you need, it is time to present them to your audience. As you start using affiliate marketing to talk about products, you need to be aware of how your audience perceives you. If your website appears to be only after their money through an overwhelming amount of affiliate links, then they are more likely to simply leave your site.