You step into the border regions of the Ethereal Plane, in the area where it overlaps with your current plane. You remain in the Border Ethereal for the duration or until you use your action to dismiss the spell. During this time, you can move in any direction. If you move up or down, every foot of movement costs an extra foot. You can see and hear the plan you originated from, but everything there looks gray, and you can’t see anything more than 60 feet away.
While on the Ethereal Plane, you can only affect and be affected by other creatures on that plane. Creatures that aren’t on the Ethereal Plance can’t perceive you and can’t interact with you, unless a special ability or magic has given them the ability to do so.