I would return the drive and buy an external drive to backup your data. There would be no need to upgrade to use the drive.
I like the Seagate USB 3.0 Backup plus drives. Works on USB 2.0 ports. I don't recommend Western Digital because of the boot problem with some of their drives. In addition, WD drives and Mavericks have had really bad results with lost data. They come formatted for PC but easy to format in Disk Utility.
Locally you'll find Best Buy has the best prices. Recent prices at Amazon.
Seagate Backup Plus 1 TB USB 3.0 $85.67
Seagate Backup Plus 2 TB USB 3.0 $99.00
Seagate Backup Plus 3 TB USB 3.0 $113.95
You can partition the larger drive for Time Machine and clone.