Is there a way to reconfigure Debian so that it could install the essential packages and configuration files? The files/packages that are missing includes the sudoer file, tcpdump, nano and a lot more. Can someone recommend a list of essential packages for Debian so I can install it manually? I am pretty sure the Linux I have is the bare minimum.
The bare minimum you describe is exactly that... A bare minimum install. It is impossible to predict what you want to use your system for and therefore impossible to suggest a list of packages.
You need to install additional software on your Debian system just like you would any other platform. Look at the APT Documentation and get familiar with it.
An important metapackage you may want to install if you plan on compiling things on that server is
build-essential
. Apart from that, you just need to install what you need.In case you find it useful this is my own incomplete list of essential packages that I tend to install in every server: