Hi Sergio,
And welcome. If you're going to develop the motor skills to play a song for your wife, and do it really well, you will have to practice it over and over till you can't believe you've played it a million times! And if you make the mistake of letting her hear you practice, she will run screaming into the night LONG before you master it. Don't EVER let her hear you practice! Only let her hear you play
I wish you the very best in making your life and your guitar vibrate in harmony with the universe. And I think you'll find some really great instruction and support here!
Peace be the journey,
Wilson