How to recognize USB to RS232 null modem cable
It would be very unusual for it to be a null-modem cable. A USB to serial converter normally allows you to add a serial port that is connected in, and works in the same way as the original COM ports fitted to desktop PCs. You would use a null-modem cable to connect, for instance, two PCs together.

If you would need a null-modem cable to connect your development kit to a desktop, you would also need one to connect to your USB converter.