This looks like steamvr gray room.
This is the room that has a light box if you look down depicting your standing/seated area if you look around behind you 360deg you should also see an arrow pointing away from you which is the direction steamvr thinks is forward. If this is not the way you are facing for forward click down arrow on steamvr on your deaktop and choose display mirror. Then click on your desktop that mirror display and look straight ahead and press Z this will put your steamvr forward view straight ahead.
Now just launch your favorite game and you should see it in the VR hmd. If it does not start, please check in task manager and kill the task that is the game you just launched and try again.
Just to be clear what you describe is completely normal an when you start stramvr and its called the gray room.. White box below you arrow pointing away and a line grid all around you.