You should make as many partitions as are required by your own use, there is no "best" way. Each partition on a drive must be mounted individually.
The basic syntax applicable to your case I think (from man mount):
mount [-fnrsvw] [-t vfstype] [-o options] device dir
... where device
is your external drive device node and dir
is the mount point.
If you need more specific help it would be best to provide your version of Red Hat and some more info on the drive. The output of lsblk -f, cfdisk /device/path, etc.
I am not a Red Hat user so will not be able to give you much more specific help myself, others here might.
Also, Red Hat is a non-free Linux, so if you have a support subscription it might be easiest to simply ask their support or visit the knowledge base.