Ok so first installation was totally fine because I had network, sound, etc... just needed the Nvidia alternate drivers. So I decided to follow the guide and do the things with multibeast.... worst idea. After a reboot I lost everything which is perfectly worked before...
Then, second installation. Something strange because it was not the exact same process...this time I had the pannel with duration of installation, first time, I had the apple on a black screen with a loading bar and the duration of installation....then, installations steps was in english after choosing french, then networks pannel...where I was obliged to choose no network...then It's running without sound and network but it's running.
Third and fourth installation were same as 2nd....
I'de like to have a clean process like the first one and I don't understand because each time before a new installation I have erased the USB key and do the same way than the first time....