Sorry for the late reply. When you say you start the game and are stuck at the guardhouse, do you mean after progressing to act 1? You aren't supposed to reach the guard house until the very end of the current version, so if you're there shortly after starting the game, that means I fucked something up bad.
If you progressed there the intended way, you don't hide by interacting with anything. Instead you have to avoid the guard's line of sight. You can hide behind the cabinet when he walks down below the boxes, or up to the window. And you can hide below the boxes at the bottom of the map when he's on his way back down (he will see you behind the cabinet when returning from the window)
If the guard is not moving or talking, but it says you need to hide, that's a bug.