I forgot my zte groove password

You're going to have to do a hard reset...THIS WILL ERASE EVERYTHING ON THE PHONE (not the sd card)
Make sure the phone is off, hold the power button, volume down and the back button (third button from the left on the bottom) AT THE SAME TIME, hold and wait, once your in the back menu use the volume button to scroll down to factory reset use the power button to select, use the power button again to scroll down to yes, and power button to select, just wait, with will shut down and turn itself back on, takes about 5 minutes to restore function. (I worked for Cricket for a long time and I know the phone well)