I cannot set up the port

I am using Window 10. I have followed the instructions. I connected from a USB port to my Arduino Nano. I set up the board to NANO but Port was greyed and did not let me set to anything. I did not pay much attention because the port was a USB and when I installed the IDE I also installed a USB driver that came with it so I thought it has recognised it. (By the way the green light on the Arduino is on by now. So I tried the Blink program, I compiled it but when I tried to transfer to the Arduino it failed. Then I went to check what ports are defined in my computer but the system administrator does not show ports. This was on my laptop. I repeated the whole thing on a desk top thinking that the problem was with the computer only to find the same thing happening. Both computers are relatively new. And the Arduino I am using is a NANO V 3.0. I am new to the Arduino and this is my first project. Can anyone help me please. Is it possible that there is something wrong with the cable.

By the way, I need to solve the problem soon since this is for a school project and will appreciate any assistance,

If it a CLONE nano you may need additional drivers for the CH340 chip. Everyone uses these They are the defacto ones for Chinese clones.

Also avoid USB 3.0 ports where possible as they are known to cause some issues. If you only have USB 3.0 then inserting a USB 2.0 POWERED hub between the port and the board often fixes things.

You didn't mention the OS but if its windows then check in device manager under Ports (com & lpt) to get the correct one. Note on some versions of windows 10 that may be a hidden option and you should enable "Show hidden devices" to see it.