Fedele,

As your are in Rome, why don't you get a mandolin and start on it, when tuned E to G it's the same fingering as the Irish Tenor banjo tuning. Start with some scales - G - A - D - E should be enough to get you going or you could use a capo?. Practice at least 30 to 60 minutes a day, without fail and you should be playing a few simple tunes and slow airs very soon. Don't worry too much about the trebles etc, at the start, they will all come in time.

Good luck