Dude it tells you exactly what you need to do.
Download a netinstall version of the latest Ubuntu.
During install you will need to select both "minimal or minimum" and "standard" packages. But to be honest this system can't do much; has no GUI. In addition to those, you need an X server which Xorg, and you need a window manager to utilize this X server basically so you can have a desktop and can have applications with graphics...the window manager you must choose for yourself but for xorg the command is probably sudo apt install xorg (it will give you a big list of things to install, but you don't need to install all of it. You do need things like
xinit, x11-xserver-utils, xserver-xorg-video-dummy, xserver-xorg-xinput-all
xserver-xorg-video-all or xserver-xorg-video-(whatever you have intel, nvidia...)
and in combination with commands like no-install-recommends...of course nothing will work without a window manager...My suggestion install xorg in full and get it working with a window manager before you start cutting down on parts of Xorg. Use the command
startx to start the window manager once Xorg and it are installed.
So after the standard and minimum, you have to install the stuff the enables graphics (Ubuntu only does this in bloat fashion forcing you to use a desktop manager which necessarily has a lot of bloat between the login manager, window manager, app indicators (system tray) menu bar, other extensions...) but as I said all you need to get graphics is technically essential parts of Xorg and a complete window manager. So what are these parts of Xorg, what do they do?
xinit (without it
startx will fail, the most essential part of Xorg)
x11-xserver-utils (think about it, gives you control Xorg, what kind..investigate)
xserver-xorg-video-dummy (a placeholder so xorg will work, but without accel.)
xserver-xorg-video-all (extensions for Xorg that support accel. for all known graphics configuraitons)
xserver-xorg-xinput-all (extension for Xorg that supports all known inputs inc. game controllers)
Note: without a login manager, you will boot to a terminal where you must specify your username and password. Once logged in, you must then type startx. Note: there security issues with xorg, thus to mitigate always use the latest version possible and block everything from the outside from coming in with iptables which is a little complicated at first, but then everything makes sense. ufw will not ensure you are not penetrated, only iptables can do it. For window manager, I recommend FLWM if you want a lightweight stacking window manager or i3wm if you want tiling window manager.