There aren't many jobs at the highest level, and getting them is an extremely competitive process.
Jobs in parkour:
Stunts for TV, film, and commercials
That's pretty much it... kinda. You can also work managing people doing either of those things, but there's really not much.
If you want to be a stunt person you must be extremely talented and extremely driven. If you really want to make it, you'll have to be willing to suffer for it. Not just from on-the-job injuries, but inconsistent work, lean times especially when breaking in, moving to where jobs are, not seeing family and friends, etc.
If you're interested in coaching, there are steps you can take. Learn parkour, and also learn how to teach others. Learn about the body and how it works. Get certifications and maintain them, and learn from those who have already walked this path what has worked for them.