When it come to business i hope this helps you overthinkers...
Before you do anything you need a business model:
How to get customers, how to service them, how to make a profit doing it.
Remember people buy because they are lazy, greedy or want to be entertained.
If your idea has 2 of those 3 elements you have a winner!
The worst business model in the world is build/buy 1x, sell 1x. Very hard to be profitable. So dont pick anything that follows that 1x1 model. Which incidentally is why most journeys on here fail as that is their business model.
At that point you have a winning business model.
Figure out where those prospects hang out and advertise/market there.
Create your ads based around which 2 of the 3 they are.
Then you only need to learn the skills to deliver that ad/marketing campaign.
That is the recipe of how you make money. Focus on that and you will profit online.