First, make sure that python (version 3) is installed . Then install the following packages.
pip install gTTS
pip install SpeechRecognition
pip install pyglet
pip install pyaudio
pip install terminaltables
pip install gpiozero pigpio
First you need to install the above packages. For light on and off functionality, you need to install pigpio package on your raspberry pi also. Then connect the LED in your desire pin and define the pin number in voice.py (line 30)
You can do whatever you want with that program.