Ciao!

The right name your instrument is "Charango" or "Charrango".

There are a lot of ways for tuning it but usually the tuning is (low to hight): G (two strings) C (two strings) E (I° hight, II° low/bass) A (two strings) E (two strings, both like the I° hight above).

The "Charango" is quite easy to play for the left hand, but hard to sturm for the right hand (the rythmic patterns usually are complicated and very fast).

Enjoy to play it!

Ciao!