I have a new imac mini with the M1 chip. The 2020 version. I am trying to connect my former vga monitor to the imac mini. Is thee an adapter or do I need a new monitor.

For starters see > Connect a display to Mac mini - Apple Support

While there are compatible USB-C to (analog) VGA adapters, a USB-C to HDMI or USB-C to DVI adapter would be a better option if your display also supports either of those.

FWIW personally I would not be happy holding back a new Mac mini with an old outdated monitor.

It is possible to run THREE monitors with an M1 Mac Mini. This is how my flight simulator is set up, and two of the monitors are VGA:

16 GB M1 Mac mini (494 GB storage) connected to a Dell Model 2007 FPb monitor (1600 x 1200 @ 60Hz) via USB-C to VGA and to a Westinghouse TV model LD2240 (1920 x 1080 @ 60 Hz) via HDMI to HDMI.  A 3rd monitor Flatron W2252TQ is connected via VGA to startech.com USB 3.0 Dual Head Graphics Adapter DVI-I to DVI-I/VGA toUSB 3 to Mac Mini.  Displaylink application was loaded and activated.