I am a girl, a riddle. For you to solve this riddle, it is necessary to understand me. I'm young, beautiful. Not looking at the youth, I know much in life.
Remarks about the translation
before edition: I am a girl a riddle. For that what to solve this riddle to you it is necessary to understand me. I young, beautiful. Not looking at the youth I know much in a life.
In the absence of more context, I opt to translate to formal 2nd person singular.
"Descartando la juventud" would be "Sin mirar a mi juventud" literally; it means: "Not taking into account how young I am...", as it would commonly take longer to acquire the knowledge I have...