Yes, you are correct. Just hook up the drive to one of the other SATA ports, plug the power in, and boot up to windows. Then right click on "my computer" and choose "manage" Choose "disk management" and initialize the new drive.
RAID is the ability to combine multiple identical drives in different ways that will either give you higher performance, or redundancy.
Due to your setup RAID will not work, so there is nothing to worry about there