Paid courses are definitely worth it but you should be very selective and go into it with the right mindset.
No one, and I mean no one can give you a step-by-step blueprint to follow word-for-word for two reasons:
1) You'll be getting a very cookie-cutter type plan to follow which is usually has limits as to how much you can really make following it. Big dollars tend to happen when you innovate.
2) Every step along the way has nuances.
The step-by-step blueprints don't tend to be rocket science. It is all in the details, the nuances. How you write your ads. How you proposition your offer. All of these things are going to be unique for each campaign and so you can't really teach it. You learn by picking your niche and getting hands-on experience in the trenches.
I also understand that the courses feel like snake-oil. Forgive them. Legitimate courses have to present themselves in that way because the hypey-words make sales. There are lots of legitimate, helpful courses that hype themselves up and in the process make themselves look like snake-oil, so don't be immediately put off by that.