A nice simple command to list block devices is 'lsblk'.
As Kent is saying OP, if you can't see the device listed in the output lsusb or lsblk then it's most likely that the disk requires more power to spin up than the Pi or it's power supply can supply.
As Kent is saying OP, if you can't see the device listed in the output lsusb or lsblk then it's most likely that the disk requires more power to spin up than the Pi or it's power supply can supply.
