There's not much to it but there are a lot of free tutorials on youtube on how to apply, use and configure an adsense account
Next, you need TRAFFIC! lots of it! For a newbie is not very profitable to rely on SEO (Search Engine Optimization = Liking Google) as you're told by many courses
Stop buying courses on "how to make money online" because most courses show you how to setup websites and tell you what to sell, or lots of other stuff that you can learn for free here on the forum of in youtube.
If you are willing to spend money on courses, then look only for "traffic" courses or "free traffic" courses or "social media traffic" courses or "viral traffic" courses and stay away from "magic traffic softwares", once YOU KNOW how to drive traffic to your websites you can start earning as much as you want and no one can take that away from you
In fact, here's a screenshot of the traffic I generated to a website I made 7 months ago when I just started making money
Since then, I told yippee ki yay to my ex boss and the alarm clock!
Once you have a budget you can start with paid traffic and list building, which you can also learn from this forum.
It is not impossible, all it takes is your will to learn!