EXPORT STAGER COMPOSITION FOR AR APP ON PHONE

Hello, 

I created a composition in stager, and wish to visualize it in an AR app on my phone. Yet, the composition / creation is way too big. How can I reduce the file format, or reduce the polygons, withing Adobe. 

I dont want to delete elements etc, as my project will become even bigger later on. I just want to reduce the size of the general file. 

I you could help me do this, would be wonderful.