The Random Reveal component is a very cool way of revealing text using random animated characters.
Go to Effects & Components > select the Components tab
Select and drag Random Reveal to the canvas
You should get random characters on the canvas and a random reveal element on the timeline
To edit the text, move the marker just after the Reveal Animation on the timeline
Double-click > type in new text
To increase or decrease the duration of the random characters, drag and adjust the Reveal Animation on the timeline.
A shorter duration makes the text reveal faster.
A longer Reveal Animation gives a slower text reveal.