During Installation, always create swap space and a separate partition for the Home directory. Always select that partition for other Linux distributions also but do not format it. And create separate users for different-different distributions like /home/ubuntu for Ubuntu, /home/arch for arch Linux and so on.
Run sudo command without password
If you don’t want to type sudo password again and again then run command
sudo visudo and append the below line at the end.
your_username ALL=NOPASSWD: ALL
Ctrl + X and
Shift + y and press Enter. That’s it.
Create user from Command line
useradd --create-home --system --shell /bin/bash --user-group your_username