This will install the most basic desktop environment without any browser or package managers etc. It’s very limited and in my opinion not worth the extra configuration to get it up and running.

# Make sure Debian is the latest and greatest

sudo apt update && sudo apt upgrade

# Install X, LXDE, VPN programs

sudo apt install xorg lxde-core tightvncserver

# Start VNC to create config file and setup your password

tightvncserver :1

# To stop VNC sever if needed

tightvncserver -kill :1

https://www.vandorp.biz/2012/01/installing-a-lightweight-lxdevnc-desktop-environment-on-your-ubuntudebian-vps/

I did not need to follow these steps and tight VNC Server was working

# Edit config file to start session with LXDE: 
nano ~/.vnc/xstartup 

# Add this at the bottom of the file: 
lxterminal & 
/usr/bin/lxsession -s LXDE &