Wiping a Macbook 2.1 clean
The old MacBook 2,1 (White 2008) could only boot from the CD/DVD drive.  Since you didn't mention that you could see the recovery partition (where you can access Disk Utility), we have to assume it's not there.

If you want to properly wipe it to ensure that all private data has been removed, do the following:


Remove the HDD from the MacBook and connect to another computer via USB to SATA adapter
Wipe with DBAN or do a Secure Erase with Disk Utility
Reinstall OS X


You could try to "hack" together a solution to get your USB to boot with rEFInd, but the work to put in to get a USB drive bootable is (IMO) a large expenditure of time just to wipe a drive.