To begin, an easy tune every body knows ! Perhaps not the best to shine as musician, but you already know it,  so the first half of the work is done.

No special trick here : Start slowly, setting the quarter note to 10 (use the small sliding triangle close to the little music note).

Step 1: fingers

Try to follow the animation, until you don't need to watch it. You will feel the tune going into your finger, some kind of automatism.

Step 2: playing in tune

Now your fingers do what you want, so it's time to listen to what your playing ! You must hear some kind of resonance betweenn your whistle sound and the animation sound: that mean you're playing in tune !

Step 3: rythm:

Try to tap the beat with your foot. If you can't get the rythm, hold the whistle down and train following the animation's rythm. Once you'll feel the beat, then you can try to play while tapping the beat with your foot

Once you control these 2 steps, then increase the speed and replay the cycle, until reaching the normal speed (50).