HI Jeanna. Both HubPages and yourself start earning when you get an AdSense account. I believe they get 40% and you 60%. And yes, all your articles will begin earning once you're accepted (assuming they remain Featured).
That said, you may not make as much as you're hoping to. Not enough to provide a living, certainly. I'm not trying to discourage - I love HubPages - but it can provide a few extra bucks each day, nothing more.
It's a fun way to supplement your income, but can't substitute for it. Best of luck!