Plug your phone to the charger.
The lights will flash if the battery was a 0% that is normal.
No you cannot turn it on or do ANYTHING while the lights are flashing.
Leave them flashing and walk away.
After 5 to 10 minutes of them flashing return to your phone and try to turn it on while plugged in. If that does not work try it unplugged.
Once your phone turns on leave it charging until full.
If your phone does not turn on after the above mentioned steps then panic.