I use ubuntu 18.4.04 LTS. But now I want to learn ethical hacking and cybersecurity. And also use it because collage take class using Zoom meeting, which is not safe according to news. So I want to use Kali Linux. Sometimes ago I want to use Windows 10 and Ubuntu dual boot. But I learn that dual boot is risky. So I didn't do this. But I can't find is it safe to do dual boot Kali Linux and Ubuntu? Can anyone tell me is the dual boot of kali Linux and Ubuntu safe or not?
Installing another distro (whether Kali or another distro) alongside Ubuntu and/or Windows is not inherently dangerous. I have had as many as five different distros on a PC (Windows plus four different Linux OS). It's what you can do with Kali (or other distros) which may be hazardous.