how can I use my old Epson Stylus 120 printer with new macs

Epson Stylus C120 driver & Software downloads - Epson Drivers (drivers-epson.com)

this site suggest they only officially support

Mac OS X 10.6 Snow Leopard

Mac OS X 10.5 Leopard

for that model, suppose you can see if the driver works

Hi,

Is this a Stylus C120 or D120?

The following official Epson support pages appear to have drivers for systems up to the latest macOS 13 Ventura:

https://epson.com/Support/Printers/Single-Function-Inkjet-Printers/Epson-Stylus-Series/Epson-Stylus-C120/s/SPT_C11C687201?review-filter=macOS+13.x

https://www.epson.eu/en_EU/support/sc/epson-stylus-d120/s/s662?selected-tab=&selected-os=macOS+13+%28Ventura%29&selected-lang=en

If necessary, reset the printing system and try to re-add the printer.

Reset the printing system on your Mac to solve a problem – Apple Support (UK)

Add a printer to your printer list so you can use it on Mac – Apple Support (UK)

You're welcome!