You need to use sudo to install packages, so please use:
sudo apt-get -f install package
If You will have issues with that, You can do it using sudo -i command, but keep in mind that You may break Your system if You will do things with the root privileges.
If Your user is added to sudoers, You will still have to use sudo command and provide password for Your actions.
sudo will elevate Your command with higher privileges, keep in mind that granting sudo rights to a command makes it powerful and may harm Your system if is not used right.
I encourage to read this article: https://wiki.debian.org/sudo
It's always better to know more, especially when You are using Linux.
Key for not breaking linux systems is a consciously use of each command.