1. Start by creating your text - Select the type tool and type in some text - then go over to essential graphics where you can change things like the size and font of your text
2. Go over to effects and search for the crop effect and add it to the text layer on the timeline
3. From the start of your text layer - Go over to effect controls and click the stopwatch icon beside right crop and change the value to 100%
4. Now move your timeline slider ahead a few seconds and then modify the value of right crop back to 0%
5. To increase the speed of the animation - simply move the keyframes closer together
