In order to determine what elements show up first in a slide when you present, use the "Animation" option from the upper settings menu bar. You'll notice each element on the slide is tagged with a number and it indicates its place in the appearance sequence. 

If all elements are tagged with number 1, it means they will all show up at once. You'll notice all elements are inside the "Step 1" box.

In order to change the elements order, just drag and drop them from "Step 1" box, to "Step 2". Consecutive steps will be added automatically for you to drag and drop elements accordingly.