USB serial devices on Linux have names like /dev/ttyACM0 or /dev/ttyUSB0. The ttySx ports are usually serial ports with DB-9 connectors built-in to the PC.
Try the command lsusb to see one line descriptions of all USB devices. My FTDI board shows up like this.
Bus 002 Device 075: ID 0403:6015 Future Technology Devices International, Ltd Bridge(I2C/SPI/UART/FIFO)
Another useful command is dmesg. Type the command after plugging in the FTDI cable. There are different models of the FTDI chip so the description and product ID might be different.
$ dmesg
usb 2-1.1: new full-speed USB device number 75 using ehci-pci
usb 2-1.1: New USB device found, idVendor=0403, idProduct=6015
usb 2-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 2-1.1: Product: FT231X USB UART
usb 2-1.1: Manufacturer: FTDI
usb 2-1.1: SerialNumber: xxxxxxxx
ftdi_sio 2-1.1:1.0: FTDI USB Serial Device converter detected
usb 2-1.1: Detected FT-X
usb 2-1.1: Number of endpoints 2
usb 2-1.1: Endpoint 1 MaxPacketSize 64
usb 2-1.1: Endpoint 2 MaxPacketSize 64
usb 2-1.1: Setting MaxPacketSize 64
usb 2-1.1: FTDI USB Serial Device converter now attached to ttyUSB0
FTDI is sometimes used generically for any USB serial device so you might see Prolific PL230x, Silicon Labs CP21xx, or CH34x. But all work on my Ubuntu desktop.