how can i get in to the hotel because i can't get out from Ecto-1

Drive by the hotel and around it you should come to a parking garage with a “Exit” sign near it. You NEED to drive by the hotel before the garage will open. Drive into the garage. You should hear an explosion and Egon will slowly lose energy. This is normal; it's the only way you can advance to the next level without being trapped in the Ecto-1.