drentooth

I have '09 370z (7AT). I had the car for more than a year now. Really wanted to get the manual and learn how to drive the stick if it's not because of a good deal the time I got the car. I've been wanting to try the paddle shifters but I never driven a stick/manual car. I kinda have an idea on how manual car works but I'm little scared that I might messed up the transmission if I don't downshift or upshift to the right gear??
Does the car will automatically do the shift for you if you're not at the right gear?? Do you have to leave your feet off the gas when shifting like the manual? I'm still a newbie on this car wanted to try the paddle shifters to add more fun while driving