"Empezar De Nuevo" (Starting Over) is a breakup song where the singer keeps saying he is done, and you can hear that he is not quite there yet. It opens on a sad, almost formal line: "Lastimosamente, nuestro destino está en otro lugar" (Sadly, our destiny is somewhere else). Then he asks to go back to the day of their first kiss, and admits the same flaws that made her fall for him are the ones that ended it.
The chorus is the heart of it: "Me va a doler el no tenerte, pero así estará mejor" (It's going to hurt not having you, but it'll be better this way). He asks her to leave "que no queden huellas" (with no traces left), hopes to be happy, and tells her "Vete y vuela lejos" (Go and fly far away). The brave face slips with "Me curo con la borrachera o con otras viejas" (I cure myself with getting drunk or with other women). Heads up: "viejas" literally means "old women", but in Colombian and Mexican slang it just means girls or women.
The second voice gets blunter and a bit petty: "Tú quieres un títere, y no soy un títere" (You want a puppet, and I'm not a puppet), and "Quieres frío, quieres calor, defínete" (You want cold, you want heat, make up your mind). Notice "como si ná", a clipped "como si nada" (as if nothing happened), the way people really talk.