Installing Kali

So i would like to install kali on my laptop using a USB but i do not want it deleting my windows 10 and the programmes on my hard drive

So how would i go about booting kali on usb and only usb without it having a affect on my hard drive

Also is there a way to backup everything on the hard drive(microsoft and the os)

Finally what happen to OTW?

thank you for any responses