I'm wanting to do a minimal install of Ubuntu 20.04 LTS on a VM I'm making. My original thought was to use either the network installer or the minimal CD, but both of those seem to be gone right now. How would I be able to get that kind of install on 20.04 LTS?
The Netinstall/Minimal image (two names for the same thing) was a byproduct of the Debian installer server build. While popular with some users, the Ubuntu developers never supported it.
Ubuntu Server recently changed to a new installer, so the Netinstall image will longer be created. The final 20.04 Netinstall image is here.
For a VM, consider using a daily cloud image: https://cloud-images.ubuntu.com/focal/current/
For Bare Metal, consider simply using an older Netinstall image, then release-upgrading those minimal packages to 20.04, then installing the rest of your system.
Netbooting the server installer is still possible, see https://discourse.ubuntu.com/t/netbooting-the-live-server-installer/14510
There are many other options: Vagrant, pre-built VMs, Ubuntu Core, Ubuntu Base, etc. It really depends upon what you want your final system configuration to look like.
