I have a basic app, which tells the user to point to certain angle for example 55. Now I have a compass which gets the azimuth, pitch and roll, I followed this tutorial http://android-coding.blogspot.ca/2012/03/create-our-android-compass.html.
I want to know whether just displaying the azimuth is correct, or would I need to use the pitch and roll as well to get an angle in degree to which the compass is point to.
The azimuth is all you need.
Pitch and roll might be interesting if you will display a 3d modell of a ship compass.
Most apps display a flat compass, for that you need only azimuth.
On the screen shot in the link you posted, you see that the red arrow points to azimut (about 44-45 degrees if I remebmer correctly)