First. Download black paper texture png. Upload it to your timeline. Put the png layer above your image layer on AE. Click Toggle Switches/Modes if you don't see the selection for Screen under Mode.

But if you want creative flexibility, you should consider scanning some black cardstock on your printer scanner 1200dpi save as png. Use a background remover website or remove it yourself on photoshop/preview etc. It looks nice if you rip, crumple, and/or fold the paper. I recommend rolling chalk on it. You can even create animations, for every fold/ crumple, scan it. Also remember to add some film shutter sounds or paper crumple/fold sfx.