Okay, I really really wanted to have Kali as fast as possible, and, of course, when you want to have something fast, it often happens goes wrong direction.
Anyway, I did everything that is written here, unfortunately I'm not able to check the sha1 because I downloaded Kali directly and it contained only the image.
So I turn on the computer, choose to boot from USB, then choose Live USB Persistence, then it looks like it's doing something (you know, black screen and letters), and then this shows up:
And that's all. Nothing happens. Later when I click esc or backspace it goes between two images similiar to this and that's the end. Can't open a Terminal, can't do anything.