Even if you're completely new to Unity, you can download it and wrap a 360 THETA video onto a sphere. Unity Personal Edition is free.
There's a writeup here:
and video with no sound. The video is intended to support the blog.
Here is the Unity Package file
360-video-file-tutorial-package.unitypackage (33.3 KB)
This is for video files, not live streaming.
If you're interested in streaming, check out
Using RICOH THETA Live view with Unity wired connection
WiFi Streaming THETA S in Unity untethered, low resolution and low framerate. Mainly for hobbyist or experimentation.