It was more a case of trying something, seeing if it worked, keeping it if it did and stopping it if it didn't. Aka trial and error.
Problem with trial and error is that unless you're naturally gifted at running a business (I'm not) or lucky (I'm not) it takes a long time to learn all the lessons you need to learn to make a successful business.
The best shortcut is a good mentor...but those are hard to find.
Edit: Having said that, Reddit has a lot of smart people on it that are able to provide sensible guidance for specific business problems.
Also: https://www.amazon.co.uk/Great-CEO-Within-Tactical-Building-... <-- this was a great framework for running various areas of a business. Wish I had stumbled across it sooner than this year.
I have no idea how to act on that nugget. All of my own attempts failed (clearly).
Show them that you are on a path to success and they will want to push you over the finish line.