Uploading Problem troubleshooting

Hello. I have a question about uploading my code to the arduino. it gave this error massage:
"avrdude: ser_open(): can't open device "\.\COM3": The system cannot find the file specified"

what do I do to open COM 3

Which model of Arduino?
What number is on the chip next to the USB connector? FT232? Atmega16U2? Ch340 or CH430?