I am a noob too so this may be incorrect. My idea would be to create a graphic of all five hearts together and have an animation (just one frame) of each that would display so animation "Zero" would be all grey hearts, then "One Heart" would be the animation with one heart there and so on.
Then in your events make a simple event to set your heart HUD to the correct animation based on how many hearts (your global heart counting variable, either the large or the small heart, i am not certain) the character currently has.
System compare variable if numberofhearts = 0
- set animation to "Zero"
If this is not what you're looking for the other advice I can offer is create a text object on your HUD layer and every tick set the text to display your variables (say set text to "Hearts: " & yourheartvariable) - this is for easier debugging while testing your game.