starter bike???
A CBR 600 probably isn't the best starter bike. They are definitely fast! Insurance would probably be pretty expensive.
Consider something like a Yamaha V-Star 650. Buy something used so if you don't like riding you can get out without losing to much money.
Take the class like everybody has mentioned. My wife took a class and she really enjoyed it. Though she decided that she would rather be a passenger on my bike!
Remember that everybody on the road is trying to kill you!
Good luck with your decision!