Mount can't find device in /etc/fstab

Create a directory that you'll use as the mountpoint for your drive:
```
mkdir /mnt/mydrive
```
Mount your drive with this command:
```
mount /dev/sdb1 /mnt/mydrive
```
Note: If you don't know your drive's device file, you can run sudo fdisk -l or lsblk to identify which one is the partition you're looking for.
Now if you run ls /mnt/mydrive, it should list your drive's files.
When you're done, don't forget to unmount your USB drive before removing it from the computer:
```
umount /dev/sdb1
```