This can be done in a million ways, but presumably Trim Paths has very little to do with it. Looks like conventional intersecting shapes and subtracting one from the other which you would do with Merge Paths operators, assuming you talk shape layers. also parts of it simply look like conventional masking of the "textures" rather than the actual geometry being removed.
Is there any way you can explain it a bit easier? HUGE noob in after effects right here
If you're a "huge noob" in After Effects, it's usually better to get a solid, foundational understanding in how to work with AE first before you try any specific effects. It will result in a lot less frustration.
It's also a good idea to make sure you have a good trainer. This old beginning in AE series by Andrew Devis is very good and FREE (the basics of using AE haven't changed much since then).