To create this important effect you need Image Lounge plugin.
Technique for creating a Typewriter Effects you'll find in this After Effects Tutorial.
Tutorial: Creating of Text Typewriter Effect in After Effects
1. Create a new composition and a import prepared background image.
2. Create a new Shape layer and apply Image Lounge effect to this layer( Effects>Image Lounge>Text Typewriter) and set the following parameters.
3. Apply to layer Glow effect (Effects>Stylize>Glow) and set the following parameters.
4. Create two keyframes for parameter 'Typing completion' from 0% to 100%.
Note: you can use many different parameters of Text Typewriter to create a desired effect.
Author: Semyon Edvabnov
To know more After Effects tips and tricks, I recommend you to read Books for After Effects.
Thank you for reading.
You can read other Tutorials in First Online Portal - After Effects Tutorials.