Need help with small circuit to convert signal to audio
The problem with this kit is that the output is a DC voltage. If you directly connect the output to the speaker, you wont hear anything..

To hear something, you have to go through several step : 


Transform the kit output from DC voltage to a sinus like waveform. The frequency of that signal has to be related to the kit output voltage level to hear a difference.
Amplify that waveform and adapt it considering the speaker inner resistance


Since you are not familiar with electronic, I suggest you to take a look at some arduino tutorial. If you combine some of them, you will be able to reach your goal.