Two ways I can think of-
Less risky:
First, try connecting a monitor via HDMI and usb keyboard and mouse. when prompted run startx and then it should feel similar to VNC at lower resolution and you should be able to poke around.
More risky:
If that doesn’t work then I would try removing the sdcard and mounting it on your Mac (with an appropriate dongle. Sdcard is removable you just need to push on it with something of the right size and shape. Ideal for this is another sdcard.
@oweno explains how to do this in this thread Some simple questions
Beware if you go the sdcard removal route you are more likely to need to start from a fresh sdcard install. Tread carefully, I have not personally tried this.