My opinion
There is a lot of content on affiliate marketing and PLR (private label rights), and it can be tough to sift through it all to find the helpful stuff. Here are some resources that I've found to help get started with affiliate marketing and PLR:
I recommend checking out Pat Flynn's Smart Passive Income Podcast, his blog, and Income School's YouTube channel for affiliate marketing. Both of these sources provide excellent information on how to start with affiliate marketing and make it successful.
As for PLR, I would recommend Ash Ambirge's The Middle Finger Project blog and podcast. A ton of great information on how to use.
Different Way
There are a lot of different ways to learn something new. You can take a class, watch a tutorial, or read a book. But sometimes, the best way to learn is by trial and error. After all, everyone learns differently, and what works for one person might not work for another. There's also the fact that some things are just better known by doing.
For example, you wouldn't want to learn how to ride a bike from a book - you're much more likely to succeed if you get on the bike and start pedalling. The same goes for learning how to cook or bake. You can watch someone else do it, but it's much more satisfying (and delicious) if you figure it out yourself.
So next time you're stuck trying to learn something new, try trial and error instead of paying for an expensive guide or watching a tutorial - it just might be the best way to learn.