Before using a partition that is on the USB drive, you must mount it on a directory. You can use the /mnt directory for this purpose. If the /mnt directory is already being used and not available, then you should create a new directory.

Use the following commands to create a new directory and then to mount partition 1 of the sdb on it:

mkdir <mountdir>

mount /dev/sdb1 <mountdir>

where, <mountdir> is the name of the directory that you want to create and on which you want to mount the partition.

After the drive is mounted on the directory, you can view it using the following command:

ls <mountdir>