I'm assuming that you didn't use the area type technique when you created your paragraphs by clicking in the upper left corner of your text area with the text tool and dragging out a text frame by moving down to the lower right.
If you did do that, just add an opacity animator, make sure that the anchor point grouping is set to character or word, then set the opacity to 0, start to 100% and end to 0% and animate the end range selector.
I did indeed use the area type technique. Will I still need to create each question and answer on a separate track?
Will I still need to create each question and answer on a separate track?
That depends on your design. I would probably approach this problem using separate layers for each question and each answer. This makes the composition look more complex, but it is actually easier to edit and animate. One of the beauties of After Effects is that you can easily separate each element in a composite and manipulate each individually. Once you get used to working this way you'll find that it is a very flexible technique.