Hi Potato Queen – thanks for writing!
I can see on your first screenshot, that you have your Range set to begin at frame 19. Your second layer has at least 1 drawing (on frame 1) – which you can not see, because it is outside your working Range.
You can adjust the Range by dragging the end of the Range bar at the very bottom of your Animation Paper window. Or you can simply hit Ctrl Home (Cmd Home on Mac) to reset Range-Start.
Please let me know if this works for you!
Best,
Niels