Mac Mini 2020
How do I use the new mac mini if my monitor is only VGA/DVI compatible?
You can connect a DVI monitor to the HDMI port or to 1 of the USB-C ports.
From HDMI you need an HDMI to DVI adapter.
https://www.apple.com/shop/product/MJVU2AM/A/apple-hdmi-to-dvi-adapter
From USB-C you need a USB-C to Digital AV Multiport adapter.
https://www.apple.com/shop/product/MUF82AM/A/usb-c-digital-av-multiport-adapter
Some less expensive third party adapter also work, but it requires testing, patients and the ability to return adapters that do not work.