Creating A Player
 
Move the camera inside the block now and you’ll see that it’s definitely hollow.
 
 
My First Room - 2
 
That cube is much large than a player but that’s OK - all we care about is it’s location.  Now use the menu item “Tools > Entity > Create > info > info_player_start” to create the player.  And voila:
 
 
And there you are!  Or he is.  Or whatever.
 
Light
 
The last thing we need to do before this room will be ready for compiling is to add a light.  Luckily, this is easy to do.  If the player isn’t currently selected, select him.  Now press the SPACE BAR to duplicate him.  Drag that copied player into the approximate center of the room in the 2D viewport by holding down CTRL+LEFT_CLICK+DRAG.  
 
Now, we go back to the entity menu.  Click on “Tools > Entity > Create > light”.  The duplicate player you created should now turn into a small green box.  That’s a light!
 
 
To create a player start, we need a new brush.  The brush will mark the location where we want the new entity to appear.  So use the pop up control at the top of the 2D viewport to create a new cube and select it.