How to positioning 2d objects in front of a 3d objects

I am a beginner with Unity. So please bare with me :) I am trying to create a scene at which there is a 3d model with a 2d object in front of it for VR purposes. The problem is that when i'm trying it in VR mode, i'm getting a duplicate of the 2d object.

Are there any suggestions on how to incorporate 2d objects with a 3d backgrounds and objects?

thanks in advance...