Things I keep in mind after reading the article

• # is for root (might need sudo depending on situation)
• $ is for regular user (no sudo required)
• # can also be used as comment in config files
• create directory is mkdir /mnt/boot
• > to redirect the output like echo hostname > /etc/hostname
• >> to append text at the bottom of a file like echo test >> /etc/pacman.conf
• ~ or $HOME point to my home directory like this /home/erik
• source to reload your changed .bashrc file like source ~/.bashrc
• install foobar is actually sudo pacman -S foobar
• start service is actually sudo systemctl start service