We need to use the Draw event so the player can see how many lives they have, the score (and later if they have ammo). Start by adding the rectangle (fill and outline)...
Now draw life images and the score.
Place the controller object somewhere in an empty spot in your rooms (top left is good as that's where it'll show up).
Test out your game - you should see something like this in the top left corner...
Get this stage of your project checked off.