Click the layer in the project panel, and the layer size will appear at the top of the panel. If you right click it in the timeline and choose, "Reveal Layer Source in Project", that will find the asset in your project panel. Also you can just type in the name in the search bar to find.
Johnny Cuevas, Editor
"I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work."
---THOMAS EDISON on inventing the light bulb.