This is really basic AE and you should take some time to learn how the program works. Start here: Basic Workflow
If you already know how AE works then you have probably opened the layer you are trying to animate in the Layer Panel. The layer panel will not show any transform effects. Make sure that you have the Composition Panel open and you should be fine.
Thank you I have had a look at the videos following the link you have provided and don't find they are useful in what I am trying to achieve.
Here is a screenshot of what I have at the moment. You can see the both layers are viewable. The 1st is the Marketing Leaders logo and the 2nd layer is the translucent image www.marketingleaders.com that cannot be seen even when the Opacity is at 100%.
I would like the 2nd layer to go from 0%-100% Opacity.
Try moving the second layer to the top of the stack. It looks to me like there is no transparency in your PNG files.
Thank you Rick! It worked! =D