Work as root (sudo -i), so ~ is /root. Answers go in /root/lab-answers/<task>. The lab creates ~/editme.txt for task 6 and saves your ~/.bashrc and sshd's settings so reset can put them back. Files in /tmp don't survive a reboot, so do the tasks in one go and run le-lab check before you reboot.

Tasks

Make ~/practice/a/b with one command, move into b, and get back home three different ways.
Find every file under /etc whose name ends in .conf, save the list to ~/conf-files.txt, count its lines, and write the count to /root/lab-answers/2.
Make sure the SSH server is running and allows password logins (turn them on if not), run ssh localhost and type a wrong password. Count the failures in sshd's journal and write the count to /root/lab-answers/3.
Make a file /tmp/private.txt that only you can read and write, check it with ls -l, then create user bob with a home directory and try sudo -u bob cat /tmp/private.txt.
Archive ~/practice to ~/practice.tar.gz with tar -czf, delete ~/practice, and restore it from the archive.
Open ~/editme.txt in vi, change before to after on the first line, save and quit. Then do the same on the second line in nano (install it if it's missing).
Add ~/scripts to PATH in ~/.bashrc, put a script hello in it with a #!/bin/bash first line, make it executable with chmod u+x, and run it as hello in a new shell.

Hints

mkdir -p, cd, cd ~, cd ../../.., cd - and pwd.
find /etc -name '*.conf' > ~/conf-files.txt, wc -l.
systemctl status sshd (ssh on Ubuntu). sshd -T | grep passwordauth should say yes; many cloud images set it to no, on Ubuntu in /etc/ssh/sshd_config.d/50-cloud-init.conf. Change it there and systemctl restart sshd (ssh on Ubuntu).
journalctl -u sshd | grep -c "Failed password" (-u ssh on Ubuntu).
chmod 600, useradd -m bob; the cat should fail.
tar -czf ~/practice.tar.gz -C ~ practice, rm -r, tar -xzf, tar -tzf to look inside.
vi: i to insert, Esc, :wq. nano: Ctrl-O to save, Ctrl-X to quit. dnf install nano on the RHEL family.
export PATH="$HOME/scripts:$PATH" in ~/.bashrc, bash or a new login to get a new shell, type hello.