Terminal code | Notion

add new user

make it a super user

[ ] why there are two [sudo] here, what are they stand for?

lock the password of the root user then logout

log in as the new user
create a file using [sudo]+command line, apt update and upgrade

set the firewall

check the status

try to log in as the root user again but failed
log in as the super user to unlock the password of the root user
then log in as the root user again!