I recommend using Unity or Unreal Engine. Those are game engines and basically you can create ‘your 3D game’ that people can walk around -and shoot stuff if you want-. You can send them the ‘exe file’ which they open as a game.
But this won’t be an ‘asap’ solution, you’ll need to learn couple of things about those softwares.
Note that Unity supports native .skp files, so you can directly import your model.