At any given time, you are in a specific location, or room. When you go into a room, the game will print a description of what you can see there. This description will contain two vital kinds of information: things in the room you can interact with or take, and a list of exits, or ways out. If you want to see the description again, you may just type LOOK.
When you want to leave a location and go to another one, you may communicate this to the game using compass directions: eg, GO NORTH. For simplicity's sake, you are allowed to omit the word GO, and to abbreviate the compass directions. So…