It all depends on
who is giving that course. Some millionaires are actually people with a personal net worth of millions but have an very indebted business net worth standing, off the top of my head I can think of Trump and possibly also Robert T. Kiyosaki of "Rich Dad, Poor Dad" game, those are not the kind of millionaires you want to learn how to make money from, because usually when people got their large net worth from parents or inheritance or real estate, their net worth tends to stay the same and they make no effort to increase it.
This phenomenon has a name, millionaires who spend more instead of investing are called UAWs, the people who do the opposite are called PAWs. These are people who earned their fortune from investing and also live on a budget, a lot of them started out poor or broke, so their revenue ends up being bigger than that of UAWs. These are the kind of people who you should buy courses from because they proved that they know how to make money. UAWs are just rich and don't know how to make more money. Somebody even wrote a book about them:
https://en.m.wikipedia.org/wiki/The_Millionaire_Next_Door#UAWs_versus_PAWsAnd by the way, Dan Lok also got rich through real estate, so if you buy a course from him you're going to be learning how to invest in real estate (or the lack thereof). I wouldn't try such a thing because homes depreciate in value and can't rebound like stocks can.
So really, when you buy a course on how to make money, it's either about real estate, stock investing, entrepreneurship, or affiliate marketing and sponsorship like putting ads on your site or getting a sponsor for your Youtube channel. If you can figure out these things yourself, then good for you. But it's always wiser to get this knowledge more quickly from someone experienced, so that you don't have to find it yourself after a long time.
Dan Lok is a scam.Check out Youtube channels like Coffeezilla and Mike Winnet,who are exposing Dan Lok.
His landlord was suing him for non-payment of his rent. Definitely not the kind of person to get advice from. What you learn from someone, you end up copying them so it you bought a course from someone who makes fraudulent business deals for example, that's what you're gonna learn