Use Chrome or Edge on desktop and connect the display via USB.
Which variant do I have? Count the USB ports on the board: 1 port (Micro-USB only) → ILI9341, 2 ports (USB-C + Micro-USB) → ST7789.
Capacitive or resistive? You usually can't tell from the board — both 3.5" variants use the same display and PCB, and the touch chips present don't reliably indicate the variant. It doesn't matter if you pick wrong: the picture is identical either way, and the only symptom of the wrong build is an unresponsive touchscreen — if touch doesn't work, just flash the other one. (Hint: capacitive reacts to a light finger touch; resistive needs a firm press or a stylus.)