Create a mask of an existing composition

So i was working on an after effect project and i got a problem that i dont know how to solve.

So i wanted that Shape (the triangle with the wave warp effect) the shape you see in the back that is an illustrator project.

My goal is that i look kind a like this and keep the wave warp animation that i have.

I want the background to be transparant to eventually but something in the back.

Any clue to help me with this?