Hello,

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. 

Enjoy.

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.