I may as well start with something I know well. When I started out as a freelance writer 20 years ago, things were very different. I wrote mostly for magazines, and I had to rely on snail mail to send out drafts and queries. I’d wait weeks for a response from my editors. Not many people had the patience for it, and few stuck around long enough to ever start earning a real income from it.
If you have previous experience as a computer programmer, or have skills in this field, then there is plenty of work you can pick up as a freelancer. If lack of confidence is holding you back, then Free Code Camp is an excellent way to get your foot in the coding door. This organization provides free courses where you will build real-life apps and programs, giving you experience and plenty to add to your CV.
Research individual companies in your desired niche: If possible, it’s always better to become an affiliate directly with a company (if they have an internal affiliate program), as no one else will be dipping into your commission rate. This is the preferred route for most of the prominent affiliate marketers, including Pat Flynn. Unfortunately, it’s also the most work, as you’ll have to do the research yourself to see who offers programs (they’re usually listed in the website footer).