Phone will not power on

Fist check to make sure the phone charged when you had it connected and charging. It may just be that it never charged.

If it's charging, try a hard reset, press and Hold down the home button, & the power button at the same time, until you see the phone turn off, and come back on and you see a black screen with a white Apple logo. Then let off both buttons. It will go back to normal if that worked.

If not, connect to iTunes via PC using A USB cable and try doing a Restore and back up