Don't be overwhelmed, especially the file system. for beginner, just focus on the HOME directory first, all you need (except when installing packages, even then you'll usually only reserved on using 'sudo' and command) is inside the HOME directory in terminal it's usually marked as tilde '~'. or 'Home' in file explorer. Try to get familiar with the terminal, it's your best friends when you need troubleshooting, etc, but using GUI is not a bad thing either.