This image mainly focuses on Isolation mode and the Opacity tool. Isolation mode is to separate a single layer or thing from the whole project and work on it solo. How I got to Isolation mode is by clicking on the left box in the second image(which is in the blue circle in the first image) and then a grey circle shows up, that’s to confirm that you are now in isolation mode.
The Opacity tool is how much you can make a certain layer be transparent or not. In the image above I circled a blue diamond shape with two arrows on each side in red. Then, I drew three red arrows pointing to three dots in the Timeline panel. These dots are keyframes, keyframes is like a marking place for a specific time you want something to happen. The Opacity tool and the keyframes work together in this image, changing the opacity and moving the keyframe are important of you want to make some form of animation to happen.
Now in the image above I am using a new tool called Position. The Position tool is in the Transform Panel in the image below
How to access the Transform panel is by clicking the little V next to the red square. Then, click on Transform and five more tools appeared, one of the tools is Position. I clicked on the stopwatch next to Position to activate it.
Back to the first image, There is a red dotted line that pinpoints to where the purple rectangle will go. At the beginning of the line there is a red outline of a box, that is the starting point of the rectangle will be placed at the beginning. At the peak of the dotted line there is another outline of a box, That is where the rectangle will go since it’s bound to the dotted line. Finally, the rectangle will smoothly go down the line to the end point at the final red outlined box.