Without knowing the details of your workflow my first guess is that you are not familiar with the Graph Editor options. Check the icons at the bottom to enable viewing the speed graph. You can choose to edit either the speed graph or the value graph. If you don't get it please study up by typing graph editor in the Search Help field at the top right corner of AE. Also, some properties don't have a speed graph to edit.
The other thing that could be wrong is that you are key framing properties that don't have a speed option. There are a bunch of values that do not have a "speed" property to fiddle with.