Check to see if there is a text preset for that.
I've said this 1 million times. It's almost impossible to learn how to use After Effects by just poking around in the program. Learn how to use to help files.
To learn how to animate text type "animate text" in the search help field at the top right corner of the app and check out the help files. You will find out how to add text animators for all kinds of properties and your eyes will be opened.
After you have done that go to the Adobe After Effects product page and check out the learning resources. Every hour you spend with quality training materials will save you 10 hours of fooling around.
There is but I can't figure out how to animate the opacity from left to right
Ok after fiddling around and reading online I figured it out. Thanks for the help!