You are not going to receive many good answers here or elsewhere. If someone would share their business secrets with the rest of the world, then they would be out of business themselves, and if they were dumb enough to do so, I would take their "advices" with a grain of salt.
In any type of niche, you'll have to learn yourself, through trial and error. And it will take years.
This probably isn’t the answer you're looking for, but it’s going to save you a lot of︀ money and protect you from those YouTube 'gurus' who claim to be trillionaires and are︁ supposedly so good-hearted and virtuous that they just have to share their 'secrets' with you.︂ ... as long as you buy their courses for 10 000 USD a month 😉