MBP to Projector

I have a MacBook Pro (Retina, 15-inch, Mid 2015) running macOS Big Sur 11.1. I also have an NEC LT30 projector, which is an older model with a VGA connector and an S-video connector. In trying to get the MBP to communicate with the projector, I have tried using two different HDMI to VGA adapters. Both times, the display on the computer just blinks in and out (like it's connecting, then disconnecting), and when the HDMI is plugged in, I cannot use the trackpad to navigate the desktop. Also, nothing comes up on the projector (it says "No Input"). I have tried rebooting both devices, without success. Any ideas on how to make this work?