Now that you have an engine and headset, you'll need artwork, sound, 3D models, and animations to fill out your virtual world. You may find assets online that are free for reuse, rip assets from popular games (if you don't plan to sell your project), make your own from scratch, or modify existing assets to suit your needs. Remember that virtual realities demand visuals and audio that appear "real" when examined close-up from all sides, even if they are stylized or abstract.
The next thing that's needed for VR dev is 3D models. There are two ways to go about this for a beginner.
The first (and easiest) option is to use openly available 3D models while you learn the other areas of VR development. The Unity and Unreal asset stores have easily available models that can be used for this purpose. There are some links below to other websites with openly available assets. This can be critical for the beginner VR dev, as it's very hard to learn so many things at once!