Bankroll

I just started practicing counting (Hi/Lo). I eventually want to do this proffesionaly (I know I have alot of studying and practicing to do).
Can anyone tell me; How much of a bankroll should I start out with when I'm ready to hit the casino's?

And is playing 1 or 2 days a week to start realistic to build up my money? (I work a day job, but I want to transition into Blackjack).
Thanks for any feedback.