I guess it was about 30 or more years ago that I started the rules of the Music Business. Now that I am primarily working in film and TV I have changed to the Entertainment Business.
It is pretty much the same as I can tell.
Rule #1
The first thing in Show Business is SHOW. The second is BUSINESS. You should spend equal time on both sides.
Rule #2
Difficult people never become easier to work with, but they do become more available for work.
Rule #3
If you are doing something that's not good for your career, It's it's not a good idea to keep doing it.
Rule #4
If you can't be #1 in the area you want to be #1 in, create your own area and be #1 there.
Rule #5
Most success and ALL failure is self-inflicted.
Also, I hope this helps. When I moved to Nashville in the early 2000s I was told "There are about 300 people in Nashville and everyone else." It seems to be the same in Los Angeles.