There is a ton of info to read, so if you join Clickbank University, you'll have plenty to keep you busy. Beginners will definitely benefit from training, as well as low-intermediate to intermediate level online marketers. I think if you have experience and have just not found luck with your previous campaigns, you might find the info pretty standard, and might only benefit from later training modules (which I was unable to view)
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).
It can take time to build up your personal freelance business. Yet, there is more demand than ever for freelancers. So, if you want to kick start making money online through freelancing you can join one of the top freelance networks, such as Flexjobs, SolidGigs, Contena, Upwork, Fiverr, or PeoplePerHour. Sign up, build your profile, upload some samples of your work and start making extra money by doing small freelance jobs.