And also the place where we live it must not have too much crime here the police is rather lax and in France we do not carry weapons me in the USA I will have to be armed too for defending myself ?
Contrary to what the gun nuts on here tell you, no, generally you don't really need a gun for self defense, but you can get one if you want.
Me? I haven't fired a gun since I retired from the military, and have yet to see a need to get one. Most places in the USA are fairly safe, even if some of the fear mongers on here would have you believe otherwise.
And, the police presence here in American cities is much more than what you have in France. I've been to places like San Remo, Nice, and Cannes.