I need help deleting my motocast ID and starting over with a new one. I created one with an email that doesn't exist.
Sorry, but per MotoCast's support file How do I uninstall MotoCast? (which tells you how to uninstall it from your pc):
There is no way to uninstall MotoCast from your device. If you have entered the incorrect settings or need to change your email/account ID, you will need to perform a factory data reset on the device.
NOTE: You will lose all your data when you do a factory reset. So be sure you backup what you need to a SD card, turn off your phone and remove the card before you proceed.
This is how you do a factory reset.
Sign out of motocast